The vehicle exploded at a protective barrier outside the security headquarters

RIYADH, April 21 (IslamOnline.net & News Agencies) - At least four people were killed and 145 others injured on Wednesday, April 21, in a car bombing targeting a headquarters of the Saudi general security services in the capital Riyadh.

Ambulance workers picked up pieces of flesh, as the state television also showed what appeared to be charred human remains, reported Agence France-Presse (AFP).

The vehicle exploded at a protective barrier outside the HQ in Riyadh's Al-Washm district, destroying dozens of other vehicles, setting fire to a nearby shop, damaging property and shattering windows over a wide area.

"I saw a car try to drive through the barrier," a witness said.

"Police stopped it and the driver turned round and it blew up".

Security forces sealed off the district as a fleet of ambulances, sirens wailing, ferried off casualties. Helicopters hovered overhead.

A series of bombings against residential compounds in the capital killed 52 people in May and November 2003.

Saudi official said the bombings bore the hallmarks of the Al-Qaeda network headed by Saudi-born Osama bin Laden.

Fighting 'Terrorism'

Crown Prince Abdullah vowed Tuesday, April 20, that the kingdom remained determined to confront "terror", following repeated clashes between security men and militants, and the discovery of five explosive-laden cars in the past week.

He was addressing a conference in Riyadh seeking scientific, educational and psychological ways to curb "terrorism".

The three-day meeting has attracted early 120 researchers and scholars from around the world to examine "Islam's position on violence and extremism".

Saudi security forces discovered Monday, April 19, two cars laden with explosives which were apparently to be used in a terror attack in the capital, a security source said.

The discovery brought to five the number of bobby-trapped cars seized in Saudi Arabia within the past week.

An interior ministry official announced Sunday the detention of eight suspects linked to recent deadly clashes between militants and security forces.

Security forces on March 15, gunned down a Yemeni described as Al-Qaeda chief of operations for Saudi Arabia and the rest of the Gulf region.