Arab foreign ministers agreed a list of sweeping sanctions Sunday designed to cripple the Syrian regime which has defied pressure to halt a bloody crackdown on protests.

The 22-member Arab League agreed to ban Syrian officials from visiting any Arab country, to freeze government assets, suspend flights and halt any transactions with the Syrian government and central bank.

Shiite rebels killed 20 people and wounded 70 others in an attack on a Sunni Islamist school in northern Yemen, a tribal source said on Sunday.

The attack targeted the Dar al-Hadith school, a Muslim fundamentalist center set up in the 1980s to train Sunni preachers in Dammaj, a suburb of the Shiite stronghold city of Saada, said the same source.

A United Arab Emirates court on Sunday sentenced a blogger and four other democracy activists to prison terms after finding them guilty of charges including insulting the Gulf state's leaders.

The State Security Court handed the blogger, Ahmed Mansour, a three-year prison sentence and the four others each received two years. They have no recourse to appeal.

The United States is to spend more than $6 billion in Iraq in 2012 even though its forces are to withdraw from the country by the end of this year, US ambassador James Jeffrey said on Sunday.

U.S. President Barack Obama announced on October 21 that the last troops would leave by year's end, but Baghdad will still host the largest American embassy in the world, with up to 16,000 people at the full mission.

Egypt's military ruler warned on Sunday of "extremely grave" consequences if the turbulent nation does not pull through its current crisis.

Field Marshal Hussein Tantawi, in comments carried by the nation's official news agency, also urged voters to turn out for the parliamentary elections starting on Monday.

Syrian forces killed at least 15 civilians on Sunday, six of them in the flashpoint region of Homs that has been under siege for several weeks in an operation to crush dissent, a rights group said.

The latest violence came as the Arab League voted to impose a raft of diplomatic and economic sanctions against President Bashar al-Assad's regime for defying an ultimatum to allow observers into the country.

Kuwait's public prosecutor on Sunday extended the detention of 24 opposition activists for three weeks pending trial for storming parliament while freeing seven others on bail, their lawyer said.

Thousands of supporters meanwhile camped outside the palace of justice for the fourth night in a row in solidarity with the detainees ahead of an opposition mass rally on Monday to press for the government's resignation.

Bahrain and Qatar on Sunday called on their citizens to leave unrest-swept Syria after the United Arab Emirates also advised its citizens to stay away.

The call, issued on the day the Arab League was deciding on sanctions against Damascus over its deadly crackdown on dissent, was issued because of instability in Syria, said Bahrain's foreign ministry.

Israeli warplanes watched two strikes on the Gaza Strip overnight in response to rocket fire from the Hamas-controlled Palestinian territory, an army spokesman said in a statement Sunday.

"In response to rocket fire towards Israel this weekend, the airforce targeted sites of terrorist activity in the south and the center of the Gaza strip during the night," said the spokesman.

Morocco's moderate Islamist party won a parliamentary election for the first time, preliminary results showed Saturday, the latest religious party to achieve huge gains on the back of the Arab Spring.

The victory by the Justice and Development Party (PJD) comes just one month after Islamists won Tunisia's post-revolution election and days before their predicted surge in Egyptian polls.