At least four people killed in ongoing prison shoot-out in northern Mexico
Inmates armed with automatic rifles in prison riot
At least four people including three police officers have been killed in an hours-long prison shoot-out involving inmates and security forces in a northern Mexican border state, authorities said.
Loud, sustained bursts of gunfire could be heard from just outside the gates of the lock-up in Ciudad Victoria, the capital of Tamaulipas state. Heavily armed security forces stood guard.
A state police officer who emerged from the prison with scratches on his face and did not give his name said inmates were armed with automatic rifles.
State security spokesman Alberto Rodriguez said in an interview with Milenio TV that three state police officers and one unidentified person were killed and six others were wounded.
The wounded were also officers, said an official with the state prosecutor's office.
Police and soldiers were mobilised to try to restore order.
"The operation continues," Mr Rodriguez said
Government photos from a helicopter overflight showed what appeared to be white smoke rising from one building. Authorities closed nearby roads, and surrounding areas were under an evacuation alert.
Relatives of prisoners said the violence apparently broke out due to a conflict between local inmates and others who were recently transferred from a prison in the border city of Nuevo Laredo.