Israeli missiles have killed 10 people and injured seven more in a attack on a bridge in south Lebanon.
Thousands of foreign people - including Britons - are trying to get out of Lebanon to escape the violence.
Royal Navy warships have arrived in the Middle East to rescue Britons, but at the moment they are stuck out at sea.
Lebanon and Israel have been attacking each other since Wednesday after a Lebanese armed group called Hezbollah seized two Israeli soldiers.
More than 130 Lebanese and at least 12 Israeli civilians have been killed.
British Prime Minister Tony Blair and the head of the United Nations want an international set of soldiers sent to Lebanon to try and calm things down.
Up to 10,000 Britons are thought to live in Lebanon.
UK government staff are trying to work out who needs to leave first.
"They may be elderly people, children, families with children. We've got to try and identify these people first," said a government spokesman.
Meanwhile, Israel is also pursuing a campaign in the Gaza Strip, where it has attacked a Palestinian government building - the foreign ministry - for the second time in a week.
The violence in Gaza started after another Israeli soldier was captured in a raid by a Palestinian group three weeks ago.