WASHINGTON - The Dallas shooting suspect who was involved in killing 5 police officers during a peaceful 'Black Lives Matter' protest against police violence last night in Dallas, Texas, USA, is dead after more than an hour holing up in a car park, local channel NBCDFW reports.

Although at first, it was reported that the suspect has been shot dead by police, it was later questioned and at the moment it is unknown whether the suspect was shot dead by the police or he died from a self-inflicted gunshot wound.

The deceased was one of the alleged perpetrators of the shooting last night, who killed five police officers and wounded another six. The suspect then barricaded himself in a parking lot and claimed to have placed bombs all over the city center.

The suspect has continued to exchange gunfire with police officers during negotiation, and has said that "the end is coming," and has vowed to hurt and kill more police. He also said he has placed several bombs in the parking lot and in other parts of downtown Dallas.

Apart from the deceased, three other suspects are being held in police custody, including a woman who was arrested in the garage and two others who were traveling in a Mercedes car.

According to NBCDFW, the police still keep a large area of downtown Dallas closed and are investigating two suspicious packages for the possibility of containing explosives.

Two separate bomb disposal squads were deployed to the premises where the suspicious packages were found, according to the local TV channel.