A UN panel said on Thursday that government forces are to blame for most rights abuses in the latest violence sweeping Syria, as a watchdog reported renewed shelling of a rebel bastion.
Meanwhile, President Bashar al-Assad said Syria's government was capable of finding a way out of the crisis gripping his country, as he met with a visiting minister from main regional ally Iran.
"Syria has been able to overcome the pressures and threats it has faced for years and is able to get out of this crisis thanks to the strength of its people and commitment to unity and independence," Assad said, quoted by SANA state news agency.
His remarks during a meeting with Reza Taqipour, Iran's communications and information technology minister, came as parliament convened for the first time since elections.
Meanwhile, the main opposition Syrian National Council began searching for a new leader after Paris-based academic Burhan Ghalioun formally resigned.
In Geneva, the UN-appointed Commission of Inquiry on Syria said the army and security forces were behind the majority of serious abuses committed since March this year as they hunt down defectors and opponents.
"Most of the serious human rights violations documented by the Commission in this update were committed by the Syrian army and security services as part of military or search operations conducted in locations known for hosting defectors and/or armed persons, or perceived as supportive of anti-government armed groups," said the panel.
The commission, set up by the UN Human Rights Council, said "a clear pattern" had emerged of government blockades to "weed out" wanted people and their families, causing children to die for lack of adequate health care.
The report comes hot on the heels of accusations by Amnesty International that "the pattern and scale of state abuses may have constituted crimes against humanity."
The London-based rights watchdog denounced the UN Security Council for failing to refer Assad to the International Criminal Court as it had done with Libya's Moamer Kadhafi.
The allegations came as government forces pounded the rebel stronghold of Rastan, in central Syria, for an 11th consecutive day, killing at least three civilians, according to a Britain-based watchdog.
Violence elsewhere killed 10 people, including four summarily executed in Basamis, a town in Idlib province, the Syrian Observatory for Human Rights said, condemning it as a "contravention of international treaties."
Government forces have been trying to overrun Rastan since May 14. Rebel fighters from the battered central city of Homs regrouped in the town, which straddles the main highway linking Damascus to the north.
Elsewhere in the country, one civilian and soldier were killed in eastern Deir Ezzor province, according to the Observatory.
More than 12,600 people have been killed in Syria since a revolt against Assad's rule broke out in March 2011, including nearly 1,500 after a UN-backed truce took effect on April 12, says the Observatory.
On the political front, Ghalioun formally resigned late on Wednesday as the chairman of the Syrian National Council, an exile group some Western and Arab states have recognised as a "legitimate representative" of Syria's people.
The SNC "office decided to accept the resignation and to ask the council president to pursue his work until the election of a new president at a meeting on June 9-10", it said in a statement announcing his resignation.
The statement also said Syria's unwillingness to stick to a peace deal brokered by UN-Arab League envoy Kofi Annan and the ongoing shelling and killing in the country were "a deliberate attempt to scupper the plan."
It called on "the international community to immediately act to adopt a new mechanism, through the Security Council, to force the Syrian regime to put an end to its crimes because as it is this regime only reacts to force".
Ghalioun announced on May 17 plans to step aside to avert divisions within the SNC after activists inside Syria accused him of monopolising power.
Meanwhile, SANA state news agency said Syria's 250-seat parliament met for the first time since May 7 elections to elect a speaker and swear in deputies, all but 41 of them new.
SANA said turnout in the election reached 51.26 percent out of 5,186,957 eligible voters, and that 30 women were elected to the People's Assembly.
It added the new members of parliament represented "all spectrums of society," without elaborating.
The regime of Assad, whose Baath party has ruled Syria unchallenged for decades, touted the elections as the first in a newly approved multi-party system.
The opposition says they boycotted both the election and a constitutional referendum, and the United States and other Western nations described them as a farce.
The US embassy in Beirut on Thursday warned Americans to be aware of prevailing tensions and violence in Lebanon, in an email to its citizens after deadly clashes in Syria's neighbour between pro- and anti-Damascus camps.