Riyadh (AsiaNews/Agencies) - Security forces in the Saudi Arabia capital Riyadh have killed a number of suspected Islamic militants during dawn clashes in a Riyadh suburb this morning. Unconfirmed reports say those killed, about five, were suspected of involvement in a foiled attack on an oil plant in the east of the country. The shooting was started by men of the security forces who surrounded and then attacked the villa where militants were hidden, in the eastern neighbourhood of Hamra. This was revealed by internal security sources.

Al-Arabiya Television said those killed, at least five, were linked to the failed attack against the oil plant in Abqaiq but this news has not been confirmed as yet. An Islamic website has claimed al-Qaeda was behind the 24 February attack.

"The clashes in Riyadh have finished and all the suspects, who were barricaded in a house in the east of Riyadh, have been killed," the Dubai-based channel reported. A large quantity of arms were said to have been seized from the villa, which had earlier been surrounded by security forces, amid a fire fight "with automatic arms fire and grenades", it said.

The Abqaiq plant is the largest pumping and refinery centre of eastern Saudi Arabia, with two-thirds of national oil production passing through.

On 24 February, Riyadh security forces killed suicide borders in at least two cars carrying explosives as they tried to ram the gates of the entrance to the plant.

The vehicles, with the logo of the Saudi company Aramco, blew up as soon as the bullets hit them and there were no blasts within the refinery as a result. According to official sources, two guards were killed and another two were injured. Soon after the foiled attack, Riyadh said output at the plant was not affected.

A website often used by Islamic militants said al-Qaeda carried out the suicide bomb attack on Abqaiq was part of al-Qaeda's campaign to force "infidels" out of the peninsula.

The al-Qaeda network has long called for attacks on Saudi oil installations, the world's top exporter of crude oil.