The British Foreign Office has warned Britons to leave Iraq immediately, citing increasing tension in the region and the risk of terrorist action.
The Foreign and Commonwealth Office has long advised against travelling to Iraq.
But in a revision to its travel advice, the FCO said: "We advise any British nationals already there to leave immediately.
"We are giving this advice because of the increasing regional tension and the risk of terrorist action."
It warned also of the danger of British citizens being used by Saddam Hussein as human shields.
The FCO said: "If you are considering going to Iraq you should be aware that British nationals were used as hostages during the 1990/1 crisis by the Iraqi regime, being held where their safety was at most risk.
"You should also be aware that there is no British diplomatic presence in Iraq to offer consular assistance."
The FCO also advised against non-essential travel to Kuwait, again because of growing tension and the possibility of terrorist action.
In a further move, it revised its travel advice on Israel and the Occupied Territories. It advised against all non-essential travel to Israel and urged British nationals to leave the West Bank and Gaza.
PA