Hungarian police say two officers wounded in an unexplained explosion are in stable condition and being treated in intensive care at a hospital.

A 23-year-old female officer suffered life-threatening injuries while her 26-year-old male partner was also seriously wounded in the blast late Saturday while they were on foot patrol in downtown Budapest. Both were recuperating after surgery.

Authorities have yet to explain the incident, after which several streets, including a major avenue, were closed to traffic while investigators searched the scene in the vicinity of the Liszt Ferenc Academy of Music.

Police on Sunday requested that witnesses come forward with information about the blast and to provide any videos or images taken at the scene.