Turkey  launched retaliatory strikes on Syrian targets as its parliament authorised further military action, but Prime Minister Recep Tayyip Erdogan said the decision was not a mandate for war.

The two moves suggested that Turkey is preparing to take a more aggressive stance against Syria in the wake of an incident on Wednesday in which mortar shells killed a woman, three of her children and a neighbour in the Turkish border town of Akcakale.

Last night’s decision was made at an emergency parliamentary session and authorises military action if the government deems it necessary.

Mr Erdogan said there was no intention of going to war with Syria, though he insisted that his nation’s borders and citizens would be defended.

“No country should dare test our determination on that,” he said.

He added the parliamentary approval was only meant to deter further shelling attacks from Syria and to allow the government to defend the country’s interests.

The UN Security Council condemned Syria “in the strongest terms” for its deadly shelling of Turkey and UN Secretary-General Ban Ki-moon urged “maximum restraint.”

After hours of haggling between Western states on the Security Council and longtime Syria backer Russia, the top UN body issued its statement, which although toughly worded was a rung down from a formal resolution.

“The members of the Security Council condemn in the strongest terms the shelling by the Syrian armed forces,” the statement said.

Syria’s UN representative, Bashar Jaafari, said his government sympathised with those killed in Wednesday’s incident.

But he said Turkey, which has long provided support and refuge for anti-Assad rebels, bore part of the blame for failing to heed repeated calls to close the border to infiltration by rebel groups and arms shipments.

Two of Syria’s key remaining allies, China and Iran, had earlier urged calm.

Diplomats said Russia opposed any reference to Syria being a threat to the region.

Abdallah Zahed Gul, a prominent Turkish analyst, said he believed Turkish authorities would carry out a limited military operation in the area where the shells were fired.

Similar legislation authorising “operations outside the Turkish borders” allow military action against Kurdish extremists in northern Iraq.

US State Department spokeswoman Victoria Nuland described the response from Turkey as “appropriate”.

“It also was designed to strengthen the deterrent effect, so that these kinds of things don’t happen again, and it was proportional,” she said.

In Berlin, German Chancellor Angela Merkel called for calm and called on both sides to show “great discretion.”

French Foreign Minister Laurent Fabius described the Syrian act as “a violation of international law that poses a serious threat to peace and international security.”

British Foreign Secretary William Hague said the incident was “completely unacceptable, not only for Turkey but for the international community as a whole”.

NATO called on Syria to immediately end its “aggressive acts” against Turkey, following a meeting late Wednesday at the request of member state Turkey.

In Cairo, the head of the Arab League Nabil al-Arabi warned of what he called a serious development on the Syrian-Turkish border and its impact on regional peace and security.

Security sources reported sporadic Turkish shelling throughout Wednesday night into yesterday.

Rami al-Idlibi, an activist in Syria’s northern Idlib province, said that at least five Turkish shells had landed near the border town of Tal Abyad. Five soldiers had been killed and 15 wounded, he said.

“There are artillery bases for the Syrian army in Tal Abyad and the Turkish shelling is targeting the army positions only,” al-Idlibi said.

The Turkish army deployed a series of artillery and anti-aircraft missiles near the northern Turkish-Syrian border last month, when Syrian shells slammed into areas inside Turkey without causing casualties.

In Syria itself, activists said the death toll from violence across the country reached 80 on Thursday, mainly in the northern provinces of Idlib and Aleppo, as well as suburban areas of the capital Damascus.

The rebels claimed they have downed a fighter jet near Aleppo, a day after suicide bombings killed at least 31 people, mainly government soldiers.

Both sides have been fighting for months for the control of Aleppo, Syria’s biggest city and the country’s commercial hub.

More than 31,000 people have been killed in Syria since the revolt against President Bashar al-Assad’s regime began nearly 19 months ago.