Presenting his panel's findings in Geneva to the UN Human Rights Council, chief UN investigator for Syria Paulo Pinheiro said in some areas Syria's fighting "bears the characteristics of a non-international armed conflict,"  the legal term for "civil war."

"Gross violations of human rights are occurring regularly," he said.

The findings were released shortly after gunmen on Wednesday stormed and destroyed a privately-owned pro-government satellite television channel located 20 kilometers from Damascus, killing seven civilians.

In Geneva, the 47-member UN panel said forces loyal to the regime of President Bashar al-Assad "may have been responsible for many of the deaths" at the village of Houla, in Syria's central province of Homs on May 24-25. The massacre left 108 people dead, including women and children.

The panel's preliminary finding prompted a walkout by Syria's ambassador Faisal Khabbaz Hamoui, who spoke of a "war of disinformation against Syria."

The 20-page report also accused rebels of the Free Syria Army of exposing children to death and injury by using them as "medical porters, messengers and cooks." Some had been going back and forth across the border with Syria.

An influx of weapons and ammunition across the border to both sides made the situation even riskier, the panel said.

Annan opts for conference

The council was told that the UN and Arab League's architect of a peace plan for Syria, Kofi Annan, would convene an international meeting in Geneva next Saturday.

Annan's deputy, Jean-Marie Guehenno, said the former UN chief had been working with key member states of the world body which have influence in Syria to try to reach a political solution.

Guehenno conceded that the six-point plan agreed by Assad and Syria's opposition on April 12 was "clearly not being implemented."

For weeks, UN veto-power Russia has pressed for the inclusion in such talks of the Syrian regime's ally, Iran, which has long been ostracized by Western powers because of its uranium refinement program and threats to Israel.

"Iran must be present. Otherwise the circle of participants will be incomplete," said Russian Foreign Minister Sergei Lavrov on Tuesday, on a visit to Jordan.

Increasingly sectarian

The panel said its findings - based on 400 interviews, imagery and documents - indicate that the conflict has become increasingly sectarian.

 "Where previously victims were targeted on the basis of their being pro- or anti-government, the Commission of Inquiry has recorded a growing number of incidents where victims appear to have been targeted because of their religious affiliation," the report said.

The panel said it was updating its secret list of identified perpetrators for possible use in future prosecutions.

The Britain-based Syrian Observatory for Human Rights said 916 people were killed in the seven days up until Tuesday, making it the "bloodiest week" of the uprising that began early last year.

ipj/rg (dpa, Reuters; AFP, AP)