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.

A car bomb exploded in central Damascus on Tuesday, wounding three people, state television reported, blaming an "armed terrorist group".

"An armed terrorist group detonated the car bomb near the Yelbugha complex in the Marjeh district of Damascus, wounding three people and causing damage to nearby buildings," the television said.

Nearly 60 people were reported killed in violence across Syria on Monday despite a hard-won ceasefire and the upcoming deployment of 300 U.N. observers to monitor the truce, a watchdog said.

The Syrian Observatory for Human Rights said on Tuesday a total 54 civilians and five soldiers were killed in various provinces.

Syria's embattled President Bashar al-Assad is "finished" and will eventually leave power "dead or alive," his Tunisian counterpart Moncef Marzouki said in a newspaper interview published on Tuesday.

"The Russians, Chinese and Iranians," who have been supporting Assad since an uprising against his rule erupted last year, "must understand that this man (Assad) is finished and that it is no longer possible to defend him," Marzouki told the pan-Arab Al-Hayat daily.

Israel decided on Tuesday to legalese three settler outposts, which the Palestinians denounced as a response to a letter from president Mahmoud Abbas demanding a halt to settlement activity if peace talks are to resume.

A ministerial committee has decided "to formalize the status of three communities which were established in the 1990s," the office of Prime Minister Benjamin Netanyahu said.

A news website editor was charged with anti-regime incitement on Monday, a prosecutor said, after he published allegations over a graft probe into a $7 billion project.

"Jamal Muhtaseb, chief editor of Gerasa News, was charged with incitement against the regime today," the military state security court prosecutor told Agence France Presse without elaborating, speaking on condition of anonymity.

U.S. President Barack Obama Monday ordered new sanctions on Syria and Iran and the "digital guns for hire" who help them oppress their people with surveillance software and monitoring technology.

Obama announced additions to the pile of U.S. sanctions already faced by the two governments as part of a wider effort to crack down on human rights abuses, atrocities and genocide, at a speech at the U.S. Holocaust Museum.

Syrian troops killed 44 people across the country on Monday, including 34 civilians in the central city of Hama alone, monitors said, as U.N. military observers toured protest centers near the capital and both the European Union and the United States imposed new sanctions.

Regime forces killed 35 people in Hama, three in the southern province of Daraa, two in the central province of Homs, one in the northwestern province of Idlib and one in the eastern protest hub of Deir Ezzor, the Local Coordination Committees, the main activist group spurring protests on the ground, said.