Militants detonated at least one car bomb during the afternoon of April 21 in the al-Nasiriyah neighborhood of central Riyadh, killing at least 10 people and injuring dozens, according to early reports from Saudi police. Eyewitnesses said a suicide bomber also died in the attack. Suicide bombers detonated car bombs in the previous two major attacks in Riyadh on Nov. 9 and May 12, 2003. The explosion appears to have targeted the headquarters of Saudi General Security, which is organizationally connected to the Interior Ministry. The blast caused extensive damage in the immediate vicinity and blew the façade off of the five-story building housing the Saudi security forces, which are responsible for guarding the royal family, among other duties. Security forces have been leading a crackdown against Islamist militants in the kingdom.