Police in Germany's southeastern state of Bavaria warned late on Saturday night that four convicts had escaped a medical facility that handles prisoners with problems like pyschiatric conditions or addiction.

It said they escaped shortly after 9 p.m. local time (1900 GMT/UTC). 

What else did police say about the escape?

"According to our current knowledge, four patients of the BKH Lerchenhaid [hospital] are suspected of first threatening an employee of the BKH," police said in a statement. 

"After that, the four occupants were able to flee towards Alburg," it said, referring to another district that's near Lerchenhaid, the location of the hospital, in the town of Straubing.

Straubing is a town of around 50,000 people in Lower Bavaria in southern Germany, located on the River Danube not so far from the borders to Austria and the Czech Republic.

Police tell residents not to pick up hitchhikers

Police warned people not to pick up hitchhikers.

"In terms of estimating a level of danger, no more details are curently available. The police nevertheless ask people not to pick up any hitchhikers or to approach the individuals," police advised. 

Instead, anyone who thinks they see the men should notify police or call the 110 emergency number.

Descriptions of the suspects released amid active search 

Police issued a follow-up statement a few hours later, including detailed descriptions, photos and identities of all four suspects, as well as information like the clothing they were last seen in. 

They included a 31-year-old Bosnian national, two 28-year-olds with German nationality and a Kosovar citizen aged 27. 

"The four escapees should be considered dangerous," police said, saying its prior advice on hitchhikers and not approaching the men still stood. 

It said helicopters and canine units were part of the large search in the Straubing area, with support from neighboring precincts mobilizing to assist. 

msh/sdi (dpa, Polizeipräsidium Niederbayern)