DAMASCUS (Agencies) - Violence flared again in Syria where three more civilians were killed on Tuesday, one of them in a raid launched after suspected mutinous soldiers shot dead three members of the security forces, a rights group said. Gunmen believed to be army deserters also abducted two security forces in a daring attack on their car near the town of Saraqeb in the northwestern province of Idlib, the Syrian Observatory for Human Rights said. After the attack, in which three members of the security forces were shot dead, Syrian troops raided Saraqeb, killing one civilian with gunfire and wounding three others, the watchdog said. A second civilian was killed in the flashpoint central city of Homs when a sniper opened fire on him from a security checkpoint, the group said. And a third down was shot dead by a sniper in the Runkuss, near Damascus, as he tried to flee the town where Syrian forces have carried out deadly raids since Sunday, the Observatory said. According to the group at least 17 people have been killed by the security forces in Rankuss since Sunday while troops were carrying more raids on Tuesday to arrest wanted militants. Living conditions also deteriorated in Rankuss, the Observatory said quoting a militant in the town who said residents have been unable to take their wounded to hospital out of fear they would be arrested by authorities. "Residents are unable to bury their dead or take their wounded to hospital because they are afraid they will be arrested by the security forces who are massively deployed in the town," the Observatory said in a statement. Security forces also set fire to the home of one man wanted by the authorities, the activist added. Meanwhile at least 29 high school students were arrested when security forces raided their school in the town of Jassim in the southern province of Daraa, cradle of more than eight months of anti-regime unrest. The latest bloodshed comes a day after UN investigators said crimes against humanity have been committed in Syria which on Sunday was hit with crippling Arab sanctions over its lethal crackdown against protesters. Evidence gathered by the Independent Commission of Inquiry on Syria found state officials guilty of murders, rape and torture, in their brutal crackdown on protesters since March. The Human Rights Council set up the commission in August to investigate human rights violations in Syria where the UN estimates at least 3,500 people have been killed. Turkey Tuesday raised the option of military intervention in neighbouring Syria while Russia rejected even an arms embargo as Damascus tries to stifle anti-government protests. Highlighting divisions among foreign powers on how to deal with the bloodshed in Syria, Turkey's foreign minister said Ankara was ready for "any scenario." Russia's foreign minister for his part said it was time to stop issuing ultimatums to Damascus. Syria is facing increased economic sanctions and condemnation from many governments over what the United Nations calls "gross human rights violations" but President Bashar al-Assad shows no sign of buckling under pressure to end his military crackdown on protesters calling for his overthrow. Western powers have long ruled out any Libyan-style military intervention in Syria to halt the crackdown, in which more than 3,500 people are believed have been killed in eight months. But Turkish Foreign Minister Ahmet Davutoglu suggested military force remained an option, albeit apparently a remote one, if Assad did not heed calls to halt the violence. "If the oppression continues, Turkey is ready for any scenario. We hope that a military intervention will never be necessary. The Syrian regime has to find a way of making peace with its own people," he told Kanal 24 TV. Davutoglu also raised the possibility of a buffer zone if the violence provoked a flood of refugees, an idea used by Ankara inside northern Iraq during the first Gulf War in 1991. WITHOUT SHAME While NATO bombing of Libya was crucial in helping rebels to oust Muammar Gaddafi, Western countries are more cautious about Syria, which lies at the heart of Middle East conflicts, borders Israel and Lebanon and maintains close ties with Iran. In Moscow, Russian Foreign Minister Sergei Lavrov rejected calls at the United Nations for an arms embargo against Syria, saying that a similar move against Libya had proved one-sided, helping rebels to topple Gaddafi in August. "We know how that worked in Libya when the arms embargo only applied to the Libyan army. The opposition received weapons, and countries like France and Qatar publicly spoke about it without shame," he told a news conference. Moscow, which has also been critical of further sanctions slapped on Syria by Western and Arab League states, has close political and strategic relations with Assad's government and has been one if its main arms suppliers. Alluding to Western powers and the Arab League, Lavrov said it was time to "stop using ultimatums" to pressure Damascus and repeated Russia's calls for dialogue between the government and its foes, whom Moscow says share blame for the bloodshed. "For the most part, armed groups are provoking the authorities. To expect the authorities to close their eyes to this is not right," Lavrov said. A U.N. commission of inquiry said Monday that Syrian military and security forces had committed crimes against humanity including murder, torture and rape, and called for an arms embargo on Syria. Russia teamed up with China last month to veto a Western-backed U.N. Security Council resolution condemning Assad's government. Both countries have oil concessions in Syria while Russia also has a little-used naval base there and provides military advisers to the Syrian army. "The longer what is happening in Syria goes on, the more it troubles us," added Lavrov. Moscow has urged Assad to implement reforms but rejects calls for his resignation and accused Western nations of trying to set the stage for armed intervention. Syria accounted for 7 percent of Russia's total of $10 billion in arms deliveries abroad in 2010, according to the Russian defense think-tank CAST. Davutoglu said the possible scenarios included setting up a buffer zone to contain any mass influx of Syrian refugees. "If tens, hundreds of thousands of people start advancing toward the Iraq, Lebanon, Turkey borders, not only Turkey but the international community may be required to take some steps such as buffer zone. We don't want that to happen but we must consider and work on that scenario," he said. The Turkish army set up a security buffer zone inside northern Iraq during in 1991 and has maintained small detachments there ever since. A former friend of Syria, Turkey has fallen out with Assad and has said it will implement some sanctions agreed by the Arab league at the weekend. Davutoglu said he was making the same mistakes as Gaddafi and Iraq's Saddam Hussein by unleashing oppression that only fueled more opposition. However, he said Damascus still had a chance to accept international observers proposed by the Arab League. TRADE VIA IRAQ Another Turkish minister said Ankara would conduct trade with the Middle East via Iraq if the violence worsened in Syria. Turkey's state-run Anatolian news agency quoted Transport Minister Binali Yildirim Tuesday as saying that Ankara would open new border gates with Iraq if necessary. Yildirim said the sanctions would not harm the Syrian people. "We plan to conduct transit shipments through new border gates in Iraq if the conditions in Syria worsen," Yildirim said. Turkey will selectively impose those sanctions announced by the Arab League to avoid harming the Syrian people, the Turkish newspaper Sabah reported Tuesday. The Arab League imposed the sanctions Sunday and the European Union weighed in one day later. Sabah said Syrian government accounts at the Turkish central bank will be suspended, official sales to the Syrian state will be halted and a travel ban will be imposed on Assad and his family. However, civil aviation flights will not be halted and Turkish Airlines services to Damascus will continue. It did not identify sources for the story.