A draft statement from G8 leaders seen by Agence France Presse on Friday warned that the international community will take "further measures" if Syria does not stop using force against protesters.

An earlier draft had specifically threatened to turn to the United Nations Security Council to impose binding sanctions, but this was later softened under pressure from Syria's traditional ally Russia, officials said.

Russia's G8 partners have asked Moscow to mediate an end to the conflict pitting Libyan leader Moammar Gadhafi's forces against pro-democracy rebels, Russian officials said Thursday.

"Requests have been voiced that Russia take upon itself the role of a mediator in settling the situation in Libya," President Dmitry Medvedev's spokeswoman Natalia Timakova told reporters at the G8 summit in Deauville.

European nations on Thursday pressed a campaign to get the U.N. Security Council to warn the Syrian government that its deadly crackdown on opposition protests could be a crime against humanity.

A draft resolution distributed to the 15 council members condemns violence used by President Bashar al-Assad's regime and calls for the lifting of a weeks-long siege against the city of Daraa.

Reinforced sanctions against Bashar al-Assad's regime in Syria will be on the agenda of the G8 summit of the world's most powerful leaders Thursday, French President Nicolas Sarkozy said.

"Clearly, the question of strengthening sanctions against Syrian leaders needs to be asked. There will be discussions about this tonight," Sarkozy told reporters at the meeting in the French resort of Deauville.

The electoral panel organizing the poll for Tunisia's constituent assembly said Thursday it had postponed the vote to October 16, despite the government wanting it to go ahead in July.

"The High Independent Panel charged with preparing elections has prepared a calendar that sets October 16 as the date of the election for the constituent assembly," said its chairman Kamel Jendoubi following a meeting with political parties.

Security forces in the Yemeni capital battled heavily armed supporters of the country's most powerful tribal leader on Thursday as President Ali Abdullah Saleh ordered the tribesman's arrest.

The leader, Sheikh Sadiq al-Ahmar, in turn accused Saleh of dragging Yemen into civil war, speaking after hours of clashes late on Wednesday and overnight in which at least 24 people were killed.

Spain's government said Thursday it had received a message from Libyan Prime Minister al-Baghdadi al-Mahmoudi seeking a ceasefire.

Spain said it was standing with other European governments, however, in seeking a set of conditions for such an agreement.

An ammunition store belonging to the powerful al-Ahmar tribe blew up in the Yemeni capital Sanaa killing 28 people, the defense ministry's 26sep.net news website said on Thursday.

"Twenty-eight people were killed in an explosion at an ammunition store belonging to Hamid al-Ahmar" in Sanaa, 26sep.net said in a text message.

Syria's pro-democracy movement has reached out to the army ahead of Friday protests that have become a weekly ritual, appealing to soldiers to join their cause.

"We urge our supporters to deliver a message to free soldiers in the Syrian army so that hand in hand the guardians of the homeland join our peaceful revolution," said Syrian Revolution, a Facebook group spurring anti-regime protests.

Thousands of followers of Shiite cleric Moqtada al-Sadr staged a mass rally in Baghdad on Thursday against U.S. forces, as Iraqi leaders consider asking for an extended American troop presence.

The demonstration comes with just months to go before U.S. forces must withdraw from Iraq, but senior American officials have said they hope Iraqi leaders will ask for troops to stay, while acknowledging the unpopularity of the soldiers.