DAMASCUS  - Twin suicide bombers targeted a Damascus police station on Tuesday killing at least 14 people, as the Syrian army launched multiple attacks on rebel positions in the northern province of Aleppo.

The blasts wounded more than 30 people, state media and the Syrian Observatory for Human Rights watchdog said.

They caused widespread damage in the capital’s central Marjeh neighbourhood, with state television broadcasting images of blood and broken glass on the pavement near the scene.

“The number of casualties after a twin suicide attack in Marjeh square has risen to 14 dead and 31 injured,” said the channel, updating an earlier toll. “The two suicide explosions took place near a police station,” it said.

The Observatory put the death toll at 15, and said one of the blasts “was caused by a suicide bomb attacker who blew himself up inside the police station.”

“A second explosion took place just outside the police station,” the Britain-based group said, without elaborating on the nature of that blast.

“The number of casualties is expected to rise because several of the wounded are in critical condition,” added the Observatory, which relies on a network of activists, doctors and lawyers for its reports.

The Syrian cabinet denounced the attack, saying “armed terrorist groups and those behind them have failed completely because of the victories achieved by our brave army,” state news agency SANA reported.

Meanwhile, in Aleppo province, the army launched multiple attacks on rebel positions, including insurgent-held areas of the key Minnigh military airbase, the Observatory said. “Parts of Minnigh military airbase were shelled by regime forces... Rebels are in control of large swathes of the airbase,” the Observatory said.

A military source told AFP heavy clashes were raging at the base for a third day, but denied any part of the airport was under rebel control.

He said the fighting was not part of a broader campaign that the regime has pledged to launch to re-take Aleppo city, large parts of which are in rebel hands, and other parts of the province. But other areas of Aleppo were under fire, two days after pro-regime media said an army campaign in the province would began within “hours or days.” Regime forces shelled the opposition-controlled villages of Deir Hafer and Al-Bab, and hit the insurgent stronghold of Marea with rockets, the Observatory said.

There were unconfirmed reports of a ground-to-ground missile strike in Aleppo province, the Observatory added.

The regime has pledged to focus its attention on Aleppo after winning a strategic victory by retaking the town of Qusayr, in the central province of Homs.

Backed by fighters from Lebanon’s powerful Shiite Hezbollah militia — a key Syrian regime ally — the army seized the town near the Lebanese border last week.

The militia’s role has raised fears about the growing regionalisation of the conflict in Syria, which began in March 2011.

The fighting has spilled over into Lebanon, where seven rockets fired from Syria landed in the Hermel region, a Hezbollah bastion, on Tuesday.

The deteriorating situation in the Golan Heights has prompted Austria to announce it would withdraw its troops from the UN monitoring force on the strategic Syrian plateau, which is partly occupied by Israel.

On Tuesday, Austria’s defence ministry said the withdrawal of the country’s 378 troops stationed in the Golan would begin on Wednesday.

The international community, led by Russia and the United States, has been pushing for an international peace conference in Geneva to discuss a political solution to the conflict.

But preparations have stalled over which countries will participate, with Iran saying Tuesday it had been invited to the conference, despite opposition from some Western countries, including France.

“Ten days ago, we received a verbal invitation to take part in this conference,” Iran’s Deputy Foreign Minister Hossein Amir Abdollahian told reporters in Moscow, without saying who extended the invitation.

Meanwhile, the UN refugee agency said Tuesday that it was in talks with Germany over the potential resettlement of 10,000 Syrians who have fled their war-torn homeland, and was probing the issue with other rich nations.

“We are working with governments, including European governments, to examine ways in which further admission programmes and or resettlement programmes for Syrians could be successfully used,” said UNHCR spokesman Adrian Edwards.

“We have been, with the German government, for some time been looking at possible resettlement for up to 10,000 Syrian refugees. Germany is one of the world’s largest refugee receiving countries, but I don’t think numbers have at this stage been discussed with others,” he told reporters.

Edwards did not elaborate on possible talks with Washington, but noted that the United States is the world’s top destination for resettlement, as opposed to temporary asylum.

Edwards said that governments were due to hold talks in Geneva on potential resettlement programmes later this month or in early July.

He underlined, however, that resettlement was just one tool used in crisis situations, and that most Syrians who have fled still wanted to go back when the fighting ends.

“Resettlement is a category that is normally reserved for very vulnerable groups, very vulnerable individuals,” he said.

“In any resettlement programme from any country, you’re talking about tiny numbers compared with the overall refugee population,” he added.

There are some 80,000 resettlement places a year worldwide, compared with 15 million refugees.

“We’re not at this stage announcing big resettlement programmes (for Syria). We’re certainly nowhere near that at this moment,” he added.

Refugee numbers have spiralled to 1.6 million after over two years of fighting in Syria between rebels and the regime of President Bashar al-Assad, with most fleeing to neighbouring Lebanon, Jordan, Turkey and Iraq, as well as to Egypt.