Adam Arnold,
Sky News Online

A US man who allegedly shot dead four police officers at a coffee shop is believed to be on the run despite earlier claims he had been surrounded.

(Clockwise, top left) Richards, Renninger, Griswold, Owens. (Right) Clemmons

Maurice Clemmons was thought to be holed up inside a house that was at the centre of a stand-off in Seattle.

Negotiators tried to lure him out using loudspeakers and explosions.

At one point, gunshots rang through the Leschi neighbourhood and it was thought he could be dead.

But when police SWAT teams entered the building more than 10 hours after surrounding it, he was not there and the property was empty.

Clemmons, 37, is suspected of killing three male officers and a female policewoman in an ambush at a coffee shop in Tacoma, Washington state, about 35 miles south of Seattle.

Lakewood police Sergeant Mark Renninger, 39, and Officers Ronald Owens, 37, Tina Griswold, 40, and Greg Richards, 42, were attacked as they worked on their laptops.

Police said Clemmons was wounded after opening fire on his victims and was believed to be still armed and at large.

A murder warrant has been issued while a reward leading to his arrest has been increased to $125,000 (£76,000).

The attack took place near McChord Air Force base.

Speaking after the SWAT raid, Pierce County Sheriff’s Office spokesman Ed Troyer said: “We have cleared the residence.

“Seattle police tactically went in and checked the residence, the suspect is not there.”

“We know that’s his last location and we know that he is suffering from a gunshot wound from when the incident occurred,” Mr Troyer told King 5 local television in Seattle.

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He also said the suspect may have been motivated by a hatred of law enforcement.

Clemmons was released on bail last week after being held for several months on charges of assaulting a police officer and child rape.

Mr Troyer said it did not appear that Clemmons’ had a specific reason for targeting the officers involved, saying he was “upset” about being detained.

“He was just targeting cops,” Mr Troyer added.