Violence in Yemen after mosque blast

(CNN) -- The government of Yemen dispatched troops and artillery to the city of Saada on Saturday after violence involving Shiite militants left 18 people dead and 48 others injured over a 24-hour period, authorities said.

Officials said they expect violence to escalate following Friday's bombing outside a mosque that targeted a local imam.

The attack occurred in Saada, nearly 150 miles (240 kilometers) north of the country's capital, Sanaa.

Yemeni government officials said a motorcycle was used to carry out an attack at the entrance of a mosque.

One official, speaking on condition of anonymity as he was not authorized to comment to media, said that many of the dead and injured were leaving Friday prayers at the Bin Salman mosque, The Associated Press reported, when the bomb exploded in a stationary car.

"I saw crowds of people and two charred vehicles -- I think one of them was the car bomb," Mohammed Abdel Bari, a worshipper, told AP. "I saw scores of people laying on the ground."

The region has been riven with violence since a Shiite Muslim rebellion in June 2004, with thousands killed in the ensuing conflict. The insurgents, now led by Abdel-Malek al-Hawthi, are critical of the authorities and their alliance with the West and the U.S. in particular.

The attack came 24 hours after the military blamed insurgents for killing seven soldiers, AP, added, sparking extra troop deployments in the region even before Friday's explosion.

In addition to the rebellion, security forces have also had to contend with attacks by al Qaeda -- the nation is the ancestral home of Osama bin Laden -- on foreigners.

Last month the U.S. embassy ordered all non-emergency staff to leave the country, one day after a rocket attack on a compound that houses Western and other international oil workers. It also followed attacks that have targeted the embassy over the last two years

And earlier this week a U.S. State Department report called Yemen's counterterrorism efforts in 2007 as "mixed" with "significant setbacks," including releasing all returned Guantanamo detainees and instituting a surrender program for terrorists with "lenient requirements."

It also criticized Yemen's weak counterterrorism laws and an "ineffective" justice system. E-mail to a friend

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