Anti-Assad protesters in Damascus
Anti-Assad protesters in DamascusReuters

Syria's army blasted rebel strongholds in Damascus with mortars on Sunday, sparking the “most intense” fighting in the capital since the revolt in the country erupted 16 months ago, a monitoring group told AFP.

The army's offensive, aimed at driving rebels of the Free Syrian Army (FSA) out of Damascus, was launched soon after Syria's foreign ministry held a press conference to deny its troops had carried out a massacre in Tremseh village on the weekend.

“The regular army fired mortar rounds into several suburbs” where FSA rebels are entrenched, Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, told AFP.

He added that fighting was heaviest in the Tadamon, Kfar Sousa, Nahr Aisha and Sidi Qadad neighborhoods, adding, “(It has) never been this intense.”

“The security forces are attempting to take control of these neighborhoods but so far they have not succeeded,” said Abdel Rahman.

The Local Coordination Committees, which organize anti-regime protests in Syria, said plumes of black smoke were billowing out of Tadamon Sunday night and that loud explosions had been heard in Nahr Aisha.

The Observatory earlier said that violence across Syria on Sunday had killed at least 55 people. They included a girl who died along with three other people when the army rained shells on the town of Rastan, a rebel stronghold in the central province of Homs.

Rights activists say more than 150 people were massacred by Syrian troops backed by pro-regime shabiha militiamen on Thursday in the village of Treimsa in central Syria.

Foreign ministry spokesman on Sunday Jihad Makdissi vehemently denied both the allegations of a massacre and the number of people reportedly killed.

“What happened was not a massacre ... It was a clash between regular forces and armed groups who do not believe in a peaceful solution,” Makdissi was quoted by AFP as having told reporters in Damascus.

“What happened was not an attack by the army on innocent civilians,” said Makdissi. He denied activists' allegations that helicopters and heavy weapons had been used in Thursday's assault on Tremseh.

“This is absolutely not true. Only troop carriers and lights weapons were used, the most powerful of weapons being RPGs (rocket-propelled grenades),” he said.

Syrian President Bashar Assad was strongly condemned for the massacre. Kofi Annan, the UN special envoy to Syria, said on Friday he was “shocked and appalled” by the massacre in Tremseh.

Annan cited in a statement “the confirmed use of heavy weaponry such as artillery, tanks and helicopters” in the attack, adding, “This is in violation of the government’s undertaking to cease the use of heavy weapons in population centers.... I condemn these atrocities in the strongest possible terms.”

U.S. Secretary of State Hillary Clinton said on Friday that she is outraged by the reports of the massacre in Syria, demanding that the UN Security Council take action to stop the violence in Syria.

Clinton said in a statement that Assad's regime is deliberately murdering innocent civilians as it tries to put down 16 months of unrest and that history will judge the Security Council if it fails to act.

“History will judge this council,” she said. “Its members must ask themselves whether continuing to allow the Assad regime to commit unspeakable violence against its own people is the legacy they want to leave.”

The Syrian government, as it has done since the beginning of the uprising in the country, blamed the massacre on “terrorists”, which the state SANA news agency claimed “had overrun the village of al-Treimseh in Hama Countryside yesterday, killing or wounding tens of Syrian civilians.”

United Nations monitors entered Tremseh on Saturday to probe the reports of the massacre.

More than 14,000 people have died in the civil war that was sparked by the Arab Spring uprisings in March 2011.

Recently the International Committee of the Red Cross declared the violence in Syria to be an “internal armed conflict” – layman's terms for a civil war – which lays the groundwork for future prosecution for war crimes.