Police in Colorado said on Monday that the shooting sprees that took place within 12 hours of each other on Sunday were most likely carried out by Matthew Murray, 24, who died in a shootout with a security guard after killing four people.

Murray is believed to have gunned down two workers at the Youth With a Mission training centre in the Denver suburb of Arvada in the early hours of Sunday morning.

He appeared several hours later at the New Life evangelical church in Colorado Springs - 120km away - where 7,000 people had gathered for worship.

Armed with an assault rifle, two handguns, a rucksack containing ammunition and smoke grenades, he killed two teenage sisters and wounded three other people before being shot dead.

Arvada Police Chief Don Wick said forensic evidence linked Murray to both crime scenes.

'Testing has confirmed that the handgun found at the church in Colorado Springs is forensically linked to shell casings found at the crime scene in Arvada.

'Based on information obtained during the course of our investigation, we believe that Matthew Murray is responsible for the crime,' he said.

Murray, described as a reclusive loner from a devout family, was reportedly dismissed from the missionary centre in 2002.

Police are probing the reasons for his dismissal.

AGENCE FRANCE-PRESSE