BERLIN - More than 300 flights have been cancelled at Germany's Duesseldorf and Cologne-Bonn airports after security personnel walked off the job to press wage demands ahead of a new round of negotiations.

The dpa news agency reported Friday that 250 workers started a day-long strike at 4 a.m., causing the cancellation of 228 flights in Duesseldorf and 78 in Cologne-Bonn.

The ver.di union seeks a roughly 30 per cent pay increase this year for private security workers, including about 2,000 airport security personnel and 32,000 others in the state of North Rhine-Westphalia. Employers have offered a 9 per cent raise.

Ver.di has staged regular strikes this year at the two airports as well as in Hamburg, where it's also seeking a new wage deal. A new round of negotiations is to start Monday.