The Federal Aviation Administration has warned U.S. carriers of a possible hijack attempt by Palestinian terrorists in Europe over the Easter weekend, the U.S. Embassy confirmed Thursday.

However, U.S. Embassy and White House officials denied a report in the tabloid Daily Express that U.S. diplomats and military personnel had been notified of the warning.The White House press secretary, Marlin Fitzwater, said the warning was issued March 16 and that it was "similar to many, many similar kinds of information and security bulletins that go out."

Fitzwater said in Washington that "it was not given to any military or diplomatic personnel but rather just to security experts at aviation airports and airlines." The notice did not mention any specific time period, such as Easter, Fitzwater said, nor did it mention a specific airline or airport.

Richard Calder, a spokesman at the embassy press office in London, said the Federal Aviation Administration office in London passed on the warning to Britain's Department of Transport and to U.S. carriers in Britain.

"I know of no warning to military personnel," Calder said.

U.S. Transportation Secretary Samuel K. Skinner expressed anger that the alert had been leaked to the news media.

"What we've learned so far is an FAA security bulletin has been made public on an unauthorized basis," Skinner told reporters in Washington.

U.S. officials in West Germany said they were unaware of any warning.

Thursday's front-page report in the Daily Express came during a political debate in Britain over whether airlines were properly informed about a radio-cassette bomb before Pan Am Flight 103 was blown apart over Lockerbie in Scotland, Dec. 21, killing 270 people. The flight originated in West Germany.

Delays of up to half an hour in flight departures were reported today at London's Heathrow Airport because of stringent security.

In another development, Independent Television News Thursday showed videotape taken by three youths who said they were able to board an empty British Airways jumbo jet at Heathrow on Monday without being challenged. The video included a shot of one youth sitting in the captain's seat in the cockpit.