At least 43 people have died in two days of Government shelling of a rebellious suburb of the Syrian capital Damascus, activists say.
The barrage is part of a fierce government offensive aimed at regaining control of parts of Damascus where rebels operate, particularly Douma.
A local activist said the shelling was "relentless" throughout yesterday and exploding shells killed people in their homes.
The Britain-based Syrian Observatory for Human Rights said 41 people died in all-day shelling of Douma yesterday, including three children and five members of a single family. At least two more were killed today.
"They (government troops) are trying to bring Douma under control, but they are being met by fierce resistance," said Rami Abdul-Rahman, the group's director. He said most of the dead were civilians.
The Local Co-ordination Committees network said 59 people were killed yesterday, most of them in Douma.
The difference in tolls illustrated the difficulty of verifying information coming out of tightly controlled Syria, where journalists and human rights groups are either banned or severely restricted.
Amateur videos posted by activists online showed bloodied bodies lying on blankets in a room and others shrouded in white sheets and placed on stretchers. "A new massacre by (president) Bashar Assad," cried a man holding a dead girl in a pink blouse, a large gash on her face.
The violence around the capital's suburbs mirrored fighting across many parts of Syria that killed dozens of other people yesterday, according to the groups.
Activists say more than 14,000 people have been killed since the uprising began in March 2011.
Much of the violence that has gripped Syria has been sanctioned by the government to crush dissent. But rebel fighters are launching increasingly deadly attacks on regime targets, and several huge suicide bombings this year suggest al Qaida or other extremists are joining the battle.
A bomb blast rocked central Damascus yesterday near a busy market and the country's main justice complex, wounding at least three people and sending a cloud of black smoke into the air.
World powers will meet tomorrow in Geneva for talks on Syria, but few observers expect a breakthrough. Syria has the protection of Russia, a veto-wielding member of the UN Security Council, and has so far been impervious to international pressure.
Russian Foreign Minister Sergey Lavrov said Moscow will not endorse a call on Mr Assad to give up power.
"External players must not dictate ... to Syrians, but, first of all, must commit to influencing all the sides in Syria to stop the violence."
US Secretary of State Hillary Clinton said it was "very clear" that all the participants at the Geneva meeting - including Russia - are on board with a transition plan created by international envoy Kofi Annan. His plan calls for the formation of a national unity government that would oversee the drafting of a new constitution and elections.
Mr Lavrov said it was "obvious that a transitional period is needed to overcome the Syrian crisis," but insisted the major powers in Geneva must focus on convincing the opposition groups to soften their demands.
Diplomatic hopes have rested on Russia to agree to a plan that would end the Assad family dynasty, which has ruled Syria for more than four decades. Russia is Syria's most important ally, protector and supplier of arms.
Russia and China have pledged to veto any international attempt to intervene militarily.