The Arab League said it agreed on Sunday to open contacts with Syria's opposition and to ask the United Nations to form a joint peacekeeping force to the unrest-swept country in moves swiftly rejected by Syria.

Arab diplomats "will open channels of communication with the Syrian opposition and offer full political and financial support, urging (the opposition) to unify its ranks," it said in a statement obtained by Agence France Presse.

Al-Qaida's Yemen branch, strongly active in the south of the impoverished nation, executed two of its members on Sunday accusing them of spying on its operations, witnesses said.

The pair were accused of planting tracking devices in the vehicles of fellow al-Qaida in the Arabian Peninsula militants and of providing Yemeni authorities, and the Saudi and U.S. intelligence services, with information.

Pope Benedict XVI has called on the Syrian leadership to respond urgently to the "legitimate" demands of its people who have been facing an increasingly bloody crackdown by President Bashar Assad's regime.

Benedict called for all sides, but especially Syria's political leaders, to enter into talks to end the uprising.

The head of a controversial Arab League observer mission to Syria has resigned, an Arab League official told Agence France Presse on Sunday.

The resignation of General Mohammed Ahmed Mustafa al-Dabi was due to be officially announced at a meeting of Arab foreign ministers in Cairo later in the day, the official said, without saying why the Sudanese former military intelligence officer had quit.

Tunisian President Moncef Marzouki arrived Sunday in Algeria for his first official visit, during which he is to push for a revival of the Arab Maghreb Union.

Algerian President Abdelaziz Bouteflika and Prime Minister Ahmed Ouyahia met him at Algiers airport at the start of his two-day visit, the final stage of a regional tour during which he has been promoting the Arab Maghreb Union.

Iran's parliamentary speaker Ali Larijani warned Iran will not forgive Gulf Arab nations if they continue backing U.S. "plots" against Tehran, local media reported on Sunday.

"We recommend to some of the countries in the region who were siding with (Iraq dictator) Saddam (Hussein) and now are siding with the U.S. plots against the Iranian nation to give it up," he was quoted as saying.

Shelling by the Syrian army killed at least 14 civilians in the central protest city of Homs on Sunday, a rights group said.

The Britain-based group said all but one of them died in Baba Amr, a rebel stronghold in the city which armed forces have targeted for more than a week, killing at least 500 people, according to activists.

Turkish jets have bombed Kurdish rebel hideouts in northern Iraq, home to members of the outlawed Kurdistan Workers' Party (PKK), the army said on Sunday.

"Two groups of targets belonging to the separatist terrorists in the regions of Zap and Kahurk were hit with efficiency in the evening of February 11 by Turkish air force jets," the general staff said in a statement posted on its website.

The Palestinians will ask the Arab League to call for the convening of an "international peace conference" during talks in Cairo, a Palestinian official told Agence France Presse on Sunday.

Azzam al-Ahmad, who is in Cairo with Palestinian President Mahmoud Abbas for talks with the Arab League representatives, said the delegation would seek backing for the conference, without giving further details.

A Turkish court Sunday placed in detention five people suspected of turning over to Syria a founder of the Free Syrian Army who is reported to have since been executed, reports said.

The suspects ordered held by the court in the southern city of Adana include a member of Turkey's National Intelligence Organization (MIT), the Anatolia news agency reported.