Turkey said Tuesday it was bringing forward by a day to April 1 a "Friends of Syria" conference in Istanbul, designed to pressure the Damascus regime into halting its crackdown on opponents.

"We have decided to bring the meeting forward for technical reasons," a Turkish diplomat said of the gathering originally set for April 2.

Syria's armed opposition is carrying out serious human rights abuses, including kidnapping, torture and execution of security force members and government supporters, a rights group said Tuesday.

"The Syrian government's brutal tactics cannot justify abuses by armed opposition groups," said Sarah Leah Whitson, Middle East director of Human Rights Watch (HRW).

The body of Coptic Pope Shenuda III left Cairo's Saint Mark's cathedral on Tuesday after a funeral service attended by thousands, and was headed to its final resting place in a 4th century monastery in the Egyptian desert.

Pallbearers struggled to get the white coffin out of the vast cathedral, pushing through a sea of mourners who threw rose petals and waved white lilies, as others pressed forward to try to touch the coffin, causing it to tilt several times.

A wave of attacks Tuesday in more than a dozen Iraqi cities killed at least 45 people on the anniversary of the U.S.-led invasion of the country, just days before Baghdad hosts a landmark Arab summit.

The violence, which left more than 190 people wounded, bore the hallmarks of al-Qaida, which typically tries to launch coordinated nationwide mass-casualty bombing campaigns, although no one immediately claimed responsibility.

U.N. secretary-general Ban Ki-moon said Tuesday that the situation in Syria has become unacceptable and called on the Security Council to unite on the issue.

"The situation in Syria has become an unacceptable and intolerable situation," Ban said in Bogor, Indonesia, where he addressed the country's peacekeepers working for the U.N.

Syrian security forces on Monday killed 30 people across the country, activists said, following unprecedented pre-dawn deadly clashes in the heart of the capital Damascus.

Nine people were killed in Deir al-Zour, six in Daraa, three in Hama, three in Idlib, three in Aleppo, three in the Damascus suburbs of Qatana and Douma, two in al-Qameshli and one in Homs, the Local Coordination Committees, the main activist group spurring protests on the ground, said.

France on Monday proposed a U.N. Security Council statement backing U.N.-Arab League envoy Kofi Annan's mission to end bloodshed in Syria and ease the international deadlock over the crisis.

With Annan and other U.N. efforts to halt the killing and gain humanitarian access already meeting resistance from President Bashar al-Assad, envoys said it had become urgent to send a "strong message" to the Damascus government.

Russia called on Syria Monday to immediately accept demands by the International Committee for the Red Cross for a daily two-hour humanitarian truce after talks with the Geneva-based body's head.

The crucial backing from Moscow to exert stronger pressure on its Soviet-era ally came after ICRC President Jakob Kellenberger huddled with Foreign Minister Sergei Lavrov for about 90 minutes.

Turkey is working relentlessly to locate and repatriate two journalists missing in Syria for about 10 days, Foreign Minister Ahmet Davutoglu said Monday, amid reports one of them had been tortured.

"We sadly do not know where they are and we do not have any confirmed information. But we are working round the clock to find them and bring them back to Turkey safe and sound," he told a news conference.

An Egyptian military court on Monday acquitted Mohammed al-Zawahiri, the brother of al-Qaida's leader Ayman, overturning a death sentence in a new trial, his lawyer and his son told Agence France Presse.

The court also acquitted Mohammed Islambouli, whose Islamist brother Khaled assassinated president Anwar Sadat in 1981, they said. They had been convicted of planning militant attacks.