Belgrade: Serbian police say unknown attackers have stabbed and robbed two Germans in Belgrade seriously injuring one of them.

Doctors at the emergency hospital say the 25-year-old man suffered serious chest injuries but was in stable condition Thursday. They say the other man was lightly injured.

Police say the attack happened earlier Thursday at Ada Ciganlija lake, the main recreation area in the Serbian capital where many cafes are located.

Police say they are searching for the assailants who took away their victims' passports and personal belongings.