Hundreds of Egyptians protested outside the Saudi embassy in Cairo on Tuesday demanding the release of an Egyptian human rights activist held by Saudi authorities who claim he possessed banned drugs.

The protesters chanted slogans against the Saudi regime as they called for the "immediate" release of Ahmed Mohammed al-Gizawi, arrested on arrival at Jeddah airport last week.

Yemen's President Abdrabuh Mansour Hadi held talks with FBI Director Robert Mueller in Sanaa Tuesday on the growing threat from al-Qaida in the country's embattled south, the state news agency reported.

They discussed "efforts in the fight against terrorism, and against al-Qaida in particular," according to SABA, which added that their talks focused on the terror network's expansion in Yemen's southern Abyan province.

Prominent Palestinian activist and writer Salameh Kaileh was arrested overnight at his home in Damascus by Syrian authorities, human rights lawyer Anwar Bunni said on Tuesday.

"The security services entered Kaileh's home in the suburb of Barzeh at 2:00 am (2300 GMT Monday) and arrested him without explanation," said Bunni.

Yemeni troops, backed by armed civilians, are advancing on southern Abyan's capital Zinjibar, under al-Qaida control since last May, security officials and the interior ministry said on Tuesday.

"The army is advancing towards the center of the city," a military official told Agence France Presse on condition of anonymity, adding that both sides have suffered casualties in fierce battles on the eastern and southern outskirts of Zinjibar that have raged since early Tuesday morning.

Iraqi President Jalal Talabani has given a visiting Kuwaiti minister a shotgun that belonged to Saddam Hussein, a source at Talabani's office in Sulaimaniyah told Agence France Presse on Tuesday.

"The Iraqi president on Friday presented to Sheikh Nasser Sabah al-Ahmed al-Jaber al-Sabah, minister of the diwan (royal court) of the Kuwaiti prince, a Brno rifle that belonged to Saddam Hussein which Talabani recovered after the liberation of Iraq" in 2003, the official said.

Yemen's sacked air force commander, who has refused to quit for weeks, on Tuesday left the post he has held for nearly three decades, the United Nations envoy to Yemen said.

"General Mohammed Saleh al-Ahmar has handed his duties over to his successor," Jamal Benomar told Agence France Presse. "I personally attended the handover ceremony."

The U.N.'s World Food Program said on Tuesday it was boosting assistance to the population in strife-torn Syria, to reach 500,000 people in the coming weeks.

"As the conflict continues, Syrians in areas affected by the violence are struggling to feed their families and WFP is deeply concerned about the potential for food insecurity," executive director Ertharin Cousin said in a statement.

Egypt's military head of state has upheld a new law barring senior officials from the regime of former strongman Hosni Mubarak of standing for the presidency, state news agency MENA reported on Tuesday.

The decision by Field Marshal Hussein Tantawi, ratifying an amendment to the political rights law approved by parliament on April 12, means former Mubarak premier Ahmed Shafiq could be barred from standing in the May election.

Citizens from Gulf Cooperation Council states will no longer need a visa to enter Tunisia, starting next month, the pan-Arab daily al-Hayat on Tuesday quoted the country's President Moncef Marzouki as saying.

"We have decided to lift the need for (entry) visas for all Gulf (nationals) starting from May in the hope of increasing visits and tourism" to Tunisia, Marzouki told the daily.

Russia on Tuesday warned both sides in Syria against disrupting the work of U.N. observers in the conflict-torn nation and called their work crucial to providing an unbiased picture on the ground.

"The more observers there are, the more information we get that is based on objective facts and that is free from speculation," Russian Foreign Minister Sergei Lavrov said while on a visit to the Central Asian state of Tajikistan.