World breaking news and pictures

BERLIN (AP) — A German union has called security personnel at airports around the country — including Frankfurt, the nation's busiest — out on a several-hour strike in a dispute over pay and conditions.

The ver.di service workers' union said members working for private security companies walked off the job early Monday morning and strikes at some sites were set to continue until midday. It said the airports involved include Duesseldorf, Hamburg, Stuttgart and Berlin's two airports as well as Frankfurt.

Ver.di says it took the step after talks with employers on conditions for some 15,000 workers failed to produce results last month. It's calling for some employees' work hours to be limited and for permanent contracts.

So-called warning strikes are used regularly as a tactic to increase pressure in German wage negotiations.