Bombers attack Saudi oil plant; TERROR: Guards open fire to foil Al Qaida suicide mission.

SUICIDE bombers who targeted the world's largest oil processing centre were thwarted by guards who fired on their cars, exploding both vehicles and killing the attackers.

Al Qaida purportedly claimed responsibility for yesterday's attack at Abqaiq, the first on an oil plant in Saudi Arabia.

The assault raised speculation that the militants were adopting the tactics of rebels across the border in Iraq, where the oil industry has been repeatedly targeted.

Al Qaida said two of its militants carried out the suicide attack.

The claim was posted on a website frequently used by terror groups but there was no way to check its authenticity.

Saudi oil minister Ali Naimi quickly announced that the attack "did not affect operations".

The huge processing plant near the Persian Gulf prepares about two-thirds of the country's oil output for export, making it a crucial link in getting Saudi crude to the market.

TWO British workers were reportedly injured after rockets exploded in the British Embassy's Green Zone compound in Baghdad last night.

The rocket attack, which happened last night, caused minor injuries, the US military said.

Two rockets were also fired in a village south east of Baghdad that included a tomb revered by Shiites. There was no damage to the tomb, officials said.

Meanwhile the Iraqi government has put Baghdad under a curfew for the second day, after yesterday's unprecedented street ban and appeals from religious leaders curbed the bloodshed that had claimed more than 140 lives across Iraq, after the bombing of a Shiite shrine.