Mechanics in Serbian flag carrier JAT were on strike for the seventh day on Thursday, and the standoff looked set to continue as the government sent in police to remove staff from a sit-in at the airport.

It is JAT's third strike in six months in a fight over owed salaries, job cuts and alleged mismanagement of the state-owned airline. All JAT planes are grounded, and management has partially covered flights with hired aircraft.

A union spokesman said that riot police arrived around midnight and escorted 400 mechanics out of a hangar they had occupied.

"The police commander came and showed us the order to kick us out. We did not want any trouble," said Nenad Trajkovic, adding they now would stand outside the hangar in shifts.

The debt-laden airline, one of the communist-era giants set up to serve the former Yugoslav market of some 20 million people, has announced drastic restructuring which includes firing or spinning off two thirds of its 3,700 workers.

Senior engineers also joined the mechanics' strike this week, demanding the resignation of top management.