Shiite militiamen freed Tuesday a top aide to Yemen's president, whose kidnapping deepened the country's crippling political crisis, said a person who helped mediate the release.

President Abedrabbo Mansour Hadi's chief of staff Ahmed Awad bin Mubarak was handed over to a committee of mediators, 10 days after he was abducted, Hussam al-Shargabi told AFP.

Fourteen candidates have registered to run against Sudan's Omar al-Bashir in a presidential vote in April, the country's electoral commission said on Tuesday.

"The electoral commission has received a total of 15 candidacies for the post of the president of the republic," commission head Mokhtar al-Assam told reporters.

A rights group on Tuesday urged Palestinian authorities to abolish the death penalty, after two new sentences were handed down this month in the Gaza Strip and the West Bank.

The Gaza-based Palestinian Center for Human Rights called for "an immediate moratorium on the use of the death penalty as a form of punishment because it violates international human rights standards."

French Foreign Minister Laurent Fabius called Tuesday for international cooperation against extremism, saying Muslims have been the first victims of "terrorism".

"No one fights under the name of religion," Fabius told journalists in Kuwait, the first Muslim country he has visited since last month's deadly attack by Islamist gunmen on French magazine Charlie Hebdo.

The Islamic State jihadist group threatened Tuesday to kill a Japanese journalist and a Jordanian pilot within 24 hours unless Amman frees a jailed female militant.

A video released on jihadist websites shows a picture of Japanese hostage Kenji Goto holding a photograph of Jordanian pilot Maaz al-Kassasbeh.

Gunmen stormed a hotel in Tripoli popular with diplomats and officials Tuesday in an attack claimed by the Islamic State group, killing at least nine people, including five foreigners, before blowing themselves up.

After setting off a car bomb outside the luxury Corinthia Hotel in Libya's capital, three militants rushed inside and opened fire, Issam al-Naass, a security services spokesman, told AFP.

Kurdish fighters battled the Islamic State group in villages around Kobane on Tuesday, a day after expelling the jihadists from the strategic Syrian town on the Turkish border.

The news prompted celebrations among residents who fled across the frontier into Turkey, with thousands gathering at the border and hoping to return, more than four months after the fighting began.

Egypt's cassation court rejected Tuesday an appeal by three secular activists who had spearheaded 2011 protests against ex-strongman Hosni Mubarak, upholding a three-year prison sentence over an illegal protest.

April 6 youth movement founder Ahmed Maher, group spokesman Mohamed Adel and renowned blogger Ahmed Douma were arrested for a protest that ended in scuffles outside a Cairo court in November 2013.

The United Nations' food agency warned on Tuesday of a looming humanitarian crisis in southern Iraq, where tens of thousands of destitute, displaced families have sought refuge from conflict.

The World Food Program (WFP) said the situation in the governorates of Najaf, Kerbala and Babel was reaching "critical levels" because of an influx of people who have fled violence in other parts of the country and no longer have any means of supporting themselves.

U.S. President Barack Obama led a heavyweight delegation to Saudi Arabia on Tuesday to meet new King Salman and shore up ties that have suffered in recent years.

The longstanding allies remain bound by shared interests in regional stability and oil.