Workers arrested at Boston airport

Police have been checking employees' backgrounds

US federal authorities have arrested at least 15 workers at Boston's Logan International airport, where the two planes that crashed into the World Trade Center in New York on 11 September took off.

The US Attorney's office said the suspects worked for a local cleaning firm and used false identification to get into secure parts of the airport.

There were no reports that any of the arrests were directly connected with the 11 September attacks.

We are seeking the arrest of 20 employees of various companies that work at Logan

US Attorney spokeswoman Samantha Martin

Criminal complaints filed against the arrested employees of the Precision Cleaning Company of Boston said they had used bogus social security numbers and alien registration cards to gain access to areas beyond the screening checkpoints.

After the September attacks, security officials at Logan airport were heavily criticised, and some of them were removed from their jobs.

The 11 September suicide attacks - including a hijacked jet that hit the Pentagon and a fourth that crashed in Pennsylvania - killed more than 3,000 people.

Samantha Martin, a spokeswoman at the office of US Attorney Michael Sullivan, said the arrests started early on Wednesday and that so far some 15 people had been taken into custody.

Security at US airports came under the spotlight after 11 September

Five more workers were also expected to be taken into custody.

"This federal involvement strengthens the ability of airports around the country to weed out individuals that have misled the federal government," said Jose Juves, spokesman for the Massachusetts Port Authority, which runs Logan.

State police have been conducting background checks of employees of businesses that have operated at Logan since 1987, Mr Juves said.

In December, some 300 workers at Salt Lake City International Airport were fired after a federal investigation showed they had lied to get their jobs.