The U.S. and French ambassadors traveled to the Damascus suburb of Daraya on Tuesday to attend a condolence ceremony for slain Syrian activist Ghiyath Matar, who reportedly died under torture, activists said.

"The ambassador of the United States arrived in Daraya along with the French ambassador to offer condolences after the death of Ghiyath Matar," the rights activists said on Twitter.

Qatari Prime Minister Sheikh Hamad bin Jassem al-Thani said on Tuesday that Syria must stop its "killing machine" and pull its army out of cities, in remarks at the end of an Arab League meeting.

"We cannot accept this killing machine. We cannot allow people to be killed this way," he told a news conference at the end of a regular meeting in Cairo of the pan-Arab body, of which Syria is a member.

Egypt's ex-intelligence chief Omar Suleiman testified on Tuesday in the trial of former president Hosni Mubarak who faces charges of involvement in the killings of protesters, state television said.

There were no further details about the testimony which was held behind closed doors.

Turkish Prime Minister Recep Tayyip Erdogan, a fervent critic of Israel, said in Egypt Tuesday recognition of a Palestinian state is not an option but an "obligation."

Addressing Arab foreign ministers as he kicked off a three-nation Arab Spring tour, the Turkish premier also said governments should not use force to repress the legitimate demands of their people.

Israeli Prime Minister Benjamin Netanyahu restated that face-to-face talks were the key to peace with the Palestinians, in talks with Germany's foreign minister who wound up a trip to Israel on Tuesday.

"Peace will be achieved only through direct negotiations and not through unilateral moves," Netanyahu told Guido Westerwelle, according to a statement issued by his office after the two met in Jerusalem on Monday.

Turkish Prime Minister Recep Tayyip Erdogan warned in comments published Tuesday that Syria could plunge into "civil war," as he began a tour of Arab countries where uprisings ousted autocratic leaders.

"I fear that matters will end with a civil war breaking out between the Alawites and the Sunnis," Erdogan said in an interview published by Egypt's independent al-Shourouk as he began his tour in Cairo.

French Foreign Minister Alain Juppe said he made little headway Tuesday in convincing Beijing to back a tough United Nations resolution condemning Syria's crackdown on pro-democracy protests.

The visiting Juppe met his Chinese counterpart Yang Jiechi and discussed the need for a resolution condemning the military crackdown on protesters, he told journalists.

Turkey is considering launching an incursion by its ground forces against Kurdish rebel bases operating in northern Iraq after a recent spate of attacks, the interior minister said on Tuesday.

"Discussions are under way for a land operation," Interior Minister Idris Naim Sahin was quoted as saying by the Anatolia news agency.

Al-Qaida in the Arabian Peninsula (AQAP) has claimed a suicide bombing in mid-August against a gathering of Shiite Huthi rebels in northern Yemen, monitoring group SITE Intelligence said on Tuesday.

Witnesses at the time said two people were killed and several wounded in the August 15 car bomb attack at a government administration complex at al-Matamma, in al-Jawf province, while leaders of the Shiite rebellion were meeting.

Pro-democracy activists called a "day of anger" across Syria on Tuesday to protest against Russia's backing for President Bashar Assad, after his security forces shot dead at least another 19 people.

"Do not support the killers," activists urged Russia in a message announcing Tuesday's action posted on The Syrian Revolution 2011, a Facebook page that has been the engine for the six-month-old revolt against Assad's regime.