BEIRUT - A Syrian Islamist rebel group on Saturday shot down a regime warplane over a village in central Hama province, a monitoring group said.

A pro-government Facebook acknowledged that a MiG-21 warplane went down over Kafr Nabuda but said it was due to "technical difficulties", denying it had been shot down. The Syrian Observatory for Human Rights said Ahrar al-Sham fired two heat-seeking missiles at the military aircraft flying over Kafr Nabuda.

"The first missile missed but the second one struck the plane," Observatory head Rami Abdel Rahman told AFP. He said the jet fighter crashed in government-held territory but that the fate of its crew remained unknown. The pro-government Facebook said the pilot of the MiG-21 "managed to eject safely" and was rescued by Syrian government forces.

Jihadist groups and rebel fighters have brought down government warplanes several times. In January 2015, the Islamic State group shot down a regime aircraft over Damascus province, killing the pilot. Moreover, at least three rockets fired from Syria hit the Turkish border town of Kilis on Saturday but no-one was injured, the local governor's office said.

The firing came after eight rockets launched from an area of Syria held by the Islamic State group killed a woman and a four-year-old boy in Kilis on Tuesday, prompting return fire from the Turkish army. On Saturday, two rockets landed in the garden of a military barracks and a building housing officers' families before a third hit the town, the Dogan news agency reported.

State-run news agency Anatolia said Turkish forces opened fire Saturday afternoon against Syrian positions held by IS, without specifying whether it was in retaliation for rockets hitting Turkish soil.

IS is not included in the landmark Syrian ceasefire deal between regime forces and rebels in force since February 27.

In the meanwhile, French President Francois Hollande said Saturday that the EU must not grant Turkey any concessions on human rights or visas in exchange for guarantees to stem the flow of migrants to Europe.

"There cannot be any concessions on the matter of human rights or the criteria for visa liberalisation," Hollande told reporters ahead of the resumption next week of tough negotiations between Turkey and the EU in Brussels.

Under a controversial draft agreement reached this week, Turkey would take back all migrants landing illegally in Greece in a bid to reduce their incentive to pay people smugglers for dangerous boat crossings to the Greek islands.

In return for every Syrian sent back from Greece, the EU would resettle one Syrian refugee from camps in Turkey -- which is hosting about 2.7 million people who have fled the conflict across the border. The question of human rights in Turkey and visa liberalisation should be "a factor for clarification and transparency in the relations between Turkey and Europe," Hollande said.

Earlier this week, the French leader said visa liberalisation for Turkish nationals, slated to go into effect in June, would only take place if Ankara met 72 conditions. Describing Turkey's willingness to readmit refugees and migrants who left illegally for Greece as "very important", he said there could be visa liberalisation but only according to the "roadmap" that had already been outlined.

"What has been agreed on is that the principle of visa liberalisation could take place... in June if all the criteria are respected and there are 72 of them," he said, one of which involves the rolling out of biometric ID cards. "If the criteria are not met, the June date will not be met either," he said.

Turkey is also demanding six billion euros ($6.6 billion) in aid, visa-free access for its nationals within Europe's passport-free Schengen zone and for swifter action to process its bid to join the EU. The plan to expel migrants en masse from Greece has sparked international criticism, with the UN's top officials on refugees and human rights questioning whether it would be legal.