British ferry ports are on a heightened state of alert for possible terrorist attacks, port officials said Tuesday. Authorities said they were conducting random searches of trucks and questioning drivers at ports including Dover on England's south coast."We've received several pieces of information indicating that ports around the country, including Dover, need to further tighten up their security in the run-up to Christmas," Port of Dover security chief Robin Dodridge told British Broadcasting Corp. radio.

The BBC reported that French and Dutch security services had warned that terrorists might drive an explosives-laden truck onto a ferry heading for Britain.

The BBC said ferry ports had been placed on "heightened emergency" alert - not the highest level, but the highest since the ratings system was established.

But the government said a security alert sent to ports last week was not the result of a specific warning.

"The government was trying to raise awareness more generally," Home Office Minister John Denham told BBC radio. "There hasn't been an overall increase in the alert state.

David Osler, industrial editor of shipping newspaper Lloyd's List, said several European ports had recently increased security amid fears of a truck-bomb attack.

"We have seen in a number of continental European ports security being stepped up over the weekend, largely because of these very fears," he said.

Dodridge said ports had received a general request to tighten security last week, with Dover also receiving a bomb threat on Friday.

"We were alerted by Kent police who had got this information from immigration services," he said.

"In accordance with our set procedures, we carried out an intensive search of the port. The bomb threat was vague. It referred to Dover but made no mention of any specific vessel."

Dodridge told Sky News television that the port received several bomb threats a year.

On Monday, Prime Minister Tony Blair said British people should be vigilant against terrorism, but not allow fear to distort normal life.

"If a terrorist thought that all he had to do to shut down the travel industry, for example, was to issue a threat against our airports, we really would be conceding defeat in the war against terrorism," Blair told the annual Lord Mayor's banquet in London's financial district.

He said barely a day went by without new intelligence about a threat to British interests, that some of the information is reliable, but some may be misinformation or gossip.

Home Secretary David Blunkett, Britain's top law enforcement official, on Sunday warned people to be particularly vigilant as Christmas approaches.

PHOTO CAPTION

British Prime Minister Tony Blair said November 11, 2002 he was bombarded almost daily with new intelligence about threats to national interests and urged Britons to be on their guard at all times. Blair addresses a news conference at Downing Street in London on Nov. 8. Photo by Pool/Reuters