DAMASCUS  - UN observers rushed on Saturday to a town in central Syria where scores of civilians were reportedly massacred, including 32 children, as the armed opposition renewed calls for air strikes on regime forces.

The Free Syrian Army (FSA) also announced it was no longer committed to the UN-backed peace plan for Syria unless there was prompt UN intervention to protect civilians.

The shelling of the town of Houla by regime forces began at around midday on Friday and continued until dawn on Saturday, the Syrian Observatory for Human Rights said, adding that UN observers had visited the area. In Damascus, UN mission chief General Robert Mood said in a statement the monitors had counted more than 92 bodies in Houla, and called the incident a "brutal tragedy." "This morning UN military and civilian observers went to Houla and counted more than 32 children and over 60 adults killed," the statement said.

French Foreign Minister Laurent Fabius condemned the massacre and said he was "making immediate arrangements for a Friends of Syria group meeting in Paris."

Earlier the rebel (FSA) urged the Friends of Syria nations to launch air strikes against President Bashar al-Assad's forces.

Turkey-based General Mustafa Ahmed al-Sheikh, head of the FSA's military council, urged "an appropriate stance after the heinous crime committed by Assad's assassin regime in the Houla region."

Earlier, opposition Syrian National Council spokeswoman Basma Kodmani said "more than 110 people were killed (half of whom are children) by the Syrian regime's forces" in Houla.

France's foreign minister condemned "the atrocities committed daily by Bashar al-Assad on his own people. With these new crimes his murderous regime plunges Syria further into horror and threatens regional stability."

Fabius said UN observers should complete their deployment in line with Annan's plan.

Saying he would speak to Annan on Sunday, Fabius added: "In the face of horror, the international community must mobilise still further to stop the martyrdom of the Syrian people."

Meanwhile, Britain said Saturday it was in urgent talks with allied countries on "a strong international response" after the bodies of more than 90 people including children were found in a Syrian town.

"We are consulting urgently with our allies on a strong international response, including at the UN Security Council, the EU and UN human rights bodies," Foreign Secretary William Hague said.

Britain will seek an urgent session of the Security Council in coming days, Hague said, in response to what he called "credible and horrific reports that a large number of civilians have been massacred" by Syrian forces in Houla.

"Our urgent priority is to establish a full account of this appalling crime and to move swiftly to ensure that those responsible are identified and held to account," he said.