A Singapore Airlines plane flying to New York from Frankfurt was diverted to Britain's Manchester Airport after a bomb threat on Monday.
The Boeing 747-400 landed safely at around 1000 GMT, police said.
"All the passengers are being disembarked. It looks like a hoax," a police spokeswoman said. She added that the authorities did not know where the threat had come from.
Monday's diversion was the fourth airline security scare in Europe in just over a week.
A spokesman for Manchester Airport in northern Britain said flight SQ26 was carrying 293 passengers and 19 crew. "The pilot declared a full emergency in mid-flight and diverted to Manchester," he said. "The plane landed... and taxied to the end of the runway. All passengers and crew have been disembarked."
He said the reason was "a specific threat to the aircraft" but could give no further details.
A spokeswoman for Singapore Airlines (SIA) said the plane was diverted due to "information received by Singapore Airlines from the German authorities."
"As the information relates to security, SIA cannot detail it," it added. The company said it would issue a full statement later.
Last Thursday, a British Airways flight from Berlin to London was diverted to Amsterdam, and two Olympic Airlines planes flying from Athens to New York were diverted to Britain and Ireland in the past week -- one of them under military escort.
Manchester Airport said the Singapore Airlines flight did not have a military escort.
