A firefight erupted Tuesday between Yemeni security forces and gunmen, dressed in police uniforms, who had been surrounding the headquarters of the interior ministry, witnesses said.

The gunmen, who were previously working unofficially in Yemen's police department, had been surrounding the ministry's headquarters in al-Hasaba district of Sanaa since Sunday, demanding that they be enrolled back into the impoverished country's police force.

The widow of Yasser Arafat on Tuesday formally asked for a French investigation into his death, bringing a complaint of assassination weeks after raising new suspicions that the former Palestinian leader was poisoned before his 2004 death in a French military hospital.

Earlier this month, Palestinian authorities gave final approval for Arafat's body to be exhumed. In recent tests of Arafat's belongings requested by his widow and the Arab satellite network Al-Jazeera, a Swiss lab detected elevated traces of polonium-210 — a rare and highly lethal substance — but said the findings were inconclusive and that Arafat's bones would have to be tested. And questions remain about the results of any additional tests after so long.

Yemeni security services have arrested a suspected al-Qaida leader, Abdulrahman al-Baihani, wanted for plotting "terrorist' attacks in the capital, state news agency Saba said Tuesday.

The suspect is "one of the most dangerous wanted al-Qaida elements and among the prominent leaders plotting to carry out acts of terrorism and sabotage in the capital," Saba quoted a high-ranking security official as saying.

Iran "will not allow the enemy to advance" in its key ally Syria, but does not yet see the need to directly intervene, the deputy chief of the Islamic republic's armed forces was quoted as saying in reports on Tuesday.

"There is still no need for Syria's circle of friends to fully enter the arena, and our assessment is that there will be no need to do so," Brigadier General Masoud Jazayeri said, according to the Shargh daily.

Syrian troops and rebels poured into commercial capital Aleppo Tuesday as both sides battened down for the long haul after 40 police were killed on day four of a pivotal battle in the nearly 17-month conflict.

A Damascus security source said the offensive which the army launched on Saturday to recapture rebel-held areas of the city of some 2.7 million people now looked likely to drag on for "several weeks".

U.S. Defense Secretary Leon Panetta on Monday said Washington was ready to help Tunisia develop its capacities to combat al-Qaida, and urged closer regional cooperation in fighting the terror network.

"The U.S. Department of Defense stands ready to help Tunisia to ensuring regional stability, to strengthen the capabilities of its defense institutions," Panetta told reporters after meeting President Moncef Marzouki.

A convoy of unarmed U.N. observers came under attack in Syria, U.N. leader Ban Ki-moon said Monday as he expressed mounting concern at the spiraling onslaught by government forces.

The five-vehicle convoy which was carrying U.N. mission chief General Babacar Gaye came under small arms fire near the protest city of Homs, a U.N. peacekeeping spokeswoman said.

Morocco's King Mohammed VI vowed on Monday to press ahead with reforms, including strengthening the independence of the judiciary and battling corruption, in a speech to mark 13 years on the throne.

"Justice, regionalization and territorial governance are among our top priorities," he said in the speech broadcast live on state television.

Syria's top diplomat in London resigned Monday in protest against the "violent and oppressive" acts of President Bashar Assad's regime, the British Foreign Office said.

The move comes after a series of defections by senior Syrian officials in recent weeks, including diplomats in several countries and top army officers.

The United States has slashed a signature Iraqi police training program as it downsizes its massive diplomatic mission amid high costs and negative Iraqi sentiment, a U.S. watchdog said on Monday.

The Special Inspector General for Iraq Reconstruction said in a report on an audit it conducted that the United States had wasted some $206 million on building facilities for the Police Development Program (PDP), which a top Iraqi interior ministry official has termed "useless."