The shootings happened shortly after 4.20am on District Road 22 in the district of Kusel, in the state of Rhineland-Palatinate.

The officers - a 24-year-old woman and 29-year-old man - said via radio that shots were being fired.

"After that, the radio connection was lost," said police spokesman Bernhard Christian Erfort.

"So we don't know what happened.

"Officers were dispatched to the site where they found the colleagues, one injured, one dead."

The injured officer also died.

Police said they are still looking for the suspects, who fled the scene.

It is not known which way they travelled and there is no description of them or the vehicle they escaped in, according to police.

At least one of the suspects is armed.

Police have asked the public not to pick up hitchhikers in the district.

District Road 22 was completely closed off in the Mayweilerhof and Ulmet areas and witnesses who noticed something suspicious were urged to contact the Kaiserslautern force.

"The background to what happened is still unclear," police said.