In US, a gunman has opened fire at a bar in California killing at least 13 people, including a police officer.

The shooting began at about 23:20 local time last night at the Borderline Bar and Grill in Thousand Oaks, California, north-west of Los Angeles.

Police said at least 10 people are known to have been injured and others are self-reporting with injuries at local hospitals.

Officials said, the suspect was found dead inside and is yet to be identified.

Police said, they recovered a handgun inside the bar. They believe, the suspect may have taken his own life but have not confirmed this.

At least 200 people were reportedly inside the Borderline Bar and Grill at the time of the attack.

A college country music night was underway when the suspect, apparently dressed in black, entered the bar and opened fire. Reports said the suspect may have used smoke grenades and at least one weapon, described as a semi-automatic handgun by witnesses.

Ventura County Sherrif Geoff Dean said, first responders had reached just three minutes after the first emergency calls from the venue were made.

Dean said Ventura Sheriff’s Sergeant Ron Helus, who later died in hospital, had tried to enter the active scene with a local highway patrolman when he was shot several times.