As the Foreign Office warns of further attacks in Saudi Arabia, Jack Straw has condemned the terror siege which left over 20 dead.

British National Michael Hamilton was killed in Sunday's attack in Al Khobar - which came to a head following a 24 hour siege masterminded by al Qaeda.

The terrorists attacked offices and residential compounds in the country's eastern province.

"I am appalled by the attacks in Al Khobar, this morning and strongly condemn these acts of terrorism," said the foreign secretary.

"I want to extend my condolences to the families of all the victims of these terrible attacks. The United Kingdom stands with the government and people of Saudi Arabia in their fight against terrorism.

"Our ambassador is travelling to Al Khobar. British officials in Al Khobar are also in close touch with the British community and the Saudi authorities."

House of Saud

The latest attack has led to fresh fears that al Qaeda is targeting the pro-West House of Saud.

It has also led to speculation that oil prices could rise further in the wake of increased instability in the Middle East.

The Foreign Office has stopped short of calling on Britons to leave Saudi Arabia - but has warned that further attacks are likely.

In a revised travel advisory, it says: "There is a continuing high threat of terrorism in Saudi Arabia. We believe that terrorists remain determined to carry out further attacks in Saudi Arabia, and that these may be in the final stages of preparation.

"The threat includes, but is not limited to, residential compounds and diplomatic and other official premises."

Sources say the embassy remains in close touch with the Saudi authorities who have enhanced security measures ahead of further possible attacks.