Egyptian police arrested 12 members of the "Black Bloc" -- a violent group opposed to the Muslim Brotherhood -- after clashes outside Cairo's presidential palace, the official MENA news agency said on Saturday.

Protesters hurled rocks and fire bombs at the walls of the presidential palace in Heliopolis, and torched a police vehicle, a security source told MENA.

Iraqi Prime Minister Nuri al-Maliki pointed a finger on Saturday at the civil war in neighboring Syria for the return of sectarian strife to Iraq, as a five-day wave of violence has killed 215 people.

And the head of the Sahwa anti-Qaida militia forces threatened war on militants if those who have killed Iraqi soldiers are not turned over.

The Organization of Islamic Cooperation urged on Saturday an "unconditional" release of two bishops kidnapped this week in Syria.

OIC secretary general Ekmeleddin Ihsanoglu condemned the kidnapping on Monday of Aleppo's Greek Orthodox Bishop Boulos Yaziji and Syriac Orthodox Bishop Yohanna Ibrahim by armed men as they were en route to the northern city from the Turkish border.

Palestinian president Mahmoud Abbas on Saturday announced the start of talks on forming a national unity government, the official WAFA news agency said.

The announcement came on the last day of the statutory two-week period after the April 13 resignation of prime minister Salam Fayyad from the Palestinian Authority that governs the West Bank.

An empty soda bottle, crushed charcoal and cola-soaked gauze -- Syrian rebels are scrambling to protect against chemical attacks by regime forces by cobbling together “do it yourself” gas masks from household items.

U.S. President Barack Obama has renewed a warning to Damascus that the use of chemical arms would cross a "red line" as evidence emerged the deadly nerve agent sarin may have been used against the rebels.

An explosion hit a police station in the eastern Libyan city of Benghazi on Saturday, causing extensive damage but no casualties, a security source said.

"The explosion damaged a large part of the building. An explosive device was probably thrown," the source said on condition of anonymity.

Gunmen killed five army intelligence soldiers in two attacks west of Baghdad while others shot dead five anti-Qaida militiamen north of the Iraqi capital on Saturday, police and doctors said.

One group of soldiers were driving near the site of a long-running anti-government protest when they were stopped by gunmen. They shot one of the gunmen, wounding him, and clashes broke out in which four of the soldiers were killed and another wounded, a police lieutenant colonel and a doctor said.

An Israeli court has ruled in favor of building a West Bank barrier across the Cremisan Valley near Bethlehem, a Roman Catholic group said on Friday vowing to appeal what it says will deprive a Christian community of its land.

The Society of St. Yves said the verdict issued on Wednesday by the Israeli Special Appeals Committee, which rules on land confiscation, will cut in half the Cremisan Valley, branding the decision "highly problematic and unjust."

European Union missions in Jerusalem and Ramallah expressed serious concerns on Friday about the demolition this week of 22 structures in eight places across the West Bank, including East Jerusalem.

The destruction displaced 28 people, including 18 children, and affected 120 other people including 57 children, a statement from EU missions in Ramallah and Jerusalem said of the actions on Tuesday and Wednesday.

U.S. President Barack Obama on Friday promised a "vigorous investigation" into reports Syrian forces fired chemical weapons and renewed his warning that proof of their use would be a "game changer."

Obama delivered the warning during talks at the White House with King Abdullah II of Jordan, as he faced rising political pressure for a military intervention in the vicious Syrian civil war.