Activists and Syrian state media say that militants from the Islamic State group have launched a major attack on the predominantly Kurdish city of Hassakeh in north eastern Syria.
The push appears to be an attempt by IS extremists to reverse some of the advances made recently by Kurdish fighters in the province.
State TV says IS extremists are battling for control of a juvenile prison still under construction on Hassakeh's southern edge and have so far attacked it with five suicide car bombs.
Until Wednesday's attack, Hassakeh had been split between government forces and Kurdish defenders.
The Britain-based Syrian Observatory for Human Rights says Syrian air force is taking part in the battle and that IS gunmen have entered the prison building.