Three suspected terrorists blew themselves up with a fourth shot dead by police following an anti-terrorist raid in Casablanca Tuesday, according to media reports.

A police officer was killed and another was seriously injured. A young child also was injured, authorities said.

The violence started when police surrounded a four-story apartment building in a Casablanca slum where the suspected terrorists were holed up, officials said.

Sources and witnesses said one of the suspects blew himself up after he was trapped on a roof terrace. A second man appeared to be on the verge of also detonating explosives when a police sniper shot him. The suspect later died of his wounds.

Among the two on the run, one suspect blew himself up in the afternoon as police were searching the neighborhood for him. He was identified as Ayyoub Raydi, the brother of Abdelfettah Raydi, who detonated explosives in an Internet cafe, killing himself and wounding four others in Casablanca March 11.

In the evening, a fourth person detonated his explosives in the middle of a boulevard.

The four were members of a gang of up to 12 that police have been looking for since March 11 bombing, police sources added.

They believed the bombers had started wearing the belts all the time to stop security forces taking them alive.

Morocco has been on the alert for attacks since 2003 when 13 suicide bombers killed themselves and 32 other people in central Casablanca in an attempt to punish the country for being a staunch ally of the United States in its "war on terror."

Moroccan authorities responded to the attacks with the arrest of thousands of alleged Islamic militants -- some accused of working with al Qaeda to plot strikes in Morocco and abroad.

Raydi and many other suspects were among the arrested, but were later released from prison under a royal pardon.

Editor: Yan