Security staff at Germany's Hamburg airport to strike Wednesday in pay dispute

A German union has called on security workers at Hamburg airport to walk off the job on Wednesday, the latest in a series of strikes staged to ramp up pressure in a pay dispute.

The ver.di union said Tuesday that security personnel will strike from 3:45 a.m. to 11 p.m. (02:45 to 22:00 GMT).

Workers at the Hamburg, Duesseldorf and Cologne-Bonn airports recently have staged several so-called "warning strikes," which are used regularly as a tactic to increase pressure in German wage negotiations. Hamburg was hit by a two-day walkout last week that caused dozens of flight cancelations.

The union and private security companies that employ the workers have failed to narrow differences over demands for a pay increase.