The government building that was wrecked by the car bombing in Riyadh. (Reuters)

Riyadh, April 21 (Reuters): A suicide car bomber destroyed a Saudi security forces building in the capital today, killing a senior officer and at least nine other people in the first major militant attack on a government target.

The bombing came days after a US warning of a possible attack in the kingdom, a key US ally and the world’s largest oil exporter which is battling a tide of Islamist extremism linked to Saudi-born Osama bin Laden’s al Qaida network.

Medical and security sources in Riyadh said more than 70 were wounded in what an official said was the sixth attempt at such a “terrorist attack” in a week. Five others were foiled.

The bomber tried to crash his vehicle into the compound in downtown Riyadh at 1100 GMT and set off a huge blast 30 metres from the building when guards tried to stop him, the Saudi interior ministry said in a statement. A Saudi official identified the dead security officer as Colonel Abdulrahman al-Saleh.

Saudi de facto ruler Crown Prince Abdullah and interior minister Prince Nayef visited the wounded. Nayef pledged that the “hand of justice” will punish the attackers.

“We advise them to hand themselves over because it is better for them... I also tell those who sympathise with them or cover for them, that they are no less criminal. Everyone must stop this or the hand of justice will reach them,” Nayef said.

“It pains us that these people call themselves Muslims and citizens of this nation,” he added.

Coinciding with a visit by a top US official to a city where 50 people died last year in suicide attacks on foreigners, the bomb tore the front off the six-storey administrative block. There were no reports of foreign deaths in the latest bombing.

Last week, Washington ordered non-essential diplomats out and said other Americans should leave, citing fresh signals of possible attacks on Western interests. The US embassy closed early after today’s bombing, a US official said.

Saudi television said children were among the injured and showed uniformed security force personnel in hospital.

“I was in the office when the blast happened. Thank God for everything,” said one bloodied and bruised survivor, breaking down in tears as he gave thanks for his escape.

Security sources confirmed security personnel were stationed in the building targeted, although the interior ministry said only that it housed traffic administrators. Its statement put no figure on casualties but said they included security forces. US deputy secretary of state Richard Armitage held talks today with Crown Prince Abdullah. They discussed Iraq and bilateral ties, which were strained after the September 11, 2001 attacks, blamed on mainly Saudi al Qaida hijackers.