BERLIN — A union representing Lufthansa cabin crew says that members based at Frankfurt airport will stage an eight-hour walkout Friday, opening a strike campaign after negotiations over pay and conditions broke down.

The UFO union announced on Thursday that the walkouts by Lufthansa cabin crew at Frankfurt, the German airline's main hub, will start at 5 a.m. (0300 GMT) and continue until 1 p.m. (1100 GMT).

UFO said earlier this week that it would stage strikes after talks broke down, but hadn't previously detailed when and where walkouts would take place. Members of UFO voted in favor of strike action in early August but the union held off on immediate action while it continued negotiations with Lufthansa.

The airline said that UFO's strike call "may lead to unscheduled flight delays and cancellations" but that "at this stage Lufthansa cannot say for sure what exact impact the strike action will have."

"Long-haul flights are the uppermost priority and, wherever possible, should not be cancelled," Lufthansa said. "Nevertheless, delays must be anticipated."