Police arrest 'armed and dangerous' man suspected of shooting officers dead

Greene is suspected of fatally shooting the officers as they sat in their patrol cars.

Earlier:

US police have identified a suspect after two Iowa officers were shot dead in separate ambush-style attacks while they were sitting in their patrol cars.

Scott Michael Greene, 46, was named as a suspect in the killings less than two miles apart in Urbandale and Des Moines.

Officers described him as armed and dangerous and have urged members of the public not to approach him.

Greene, of Urbandale, is 5ft 11in with brown hair and green eyes. He was last known to be driving a blue 2011 Ford F-150 with the Iowa licence number 780 YFR.

The alert was raised after an Urbandale Police Department officer was found with gunshot wounds after reports of a shooting at 1.06am local time.

Authorities from several agencies who flooded the area after that incident discovered a Des Moines officer had also been shot in a patrol car at an intersection, just 20 minutes later.

Des Moines Police Sgt Paul Parizek said the shootings happened less than two miles apart, and both took place along main streets which cut through residential areas.

"There's somebody out there shooting police officers. We hope to find him before somebody else gets hurt," said Sgt Parizek, who stopped briefly during a news conference as he struggled to control his emotions.

The shootings follow a spate of US police killings, including ambushes of officers in Dallas, Texas, and Baton Rouge, Louisiana.

Five officers were killed in Dallas on July 7 and three were killed later that month in Baton Rouge.

Officers in Urbandale and Des Moines are now conducting patrols in pairs for protection, and Sgt Parizek added: "There is a clear and present danger to police officers."

Urbandale Sgt Chad Underwood said he believes this is the first time an officer in his department has been shot in the line of duty.

Urbandale officers are equipped with body cameras, but they do not run constantly and it is unclear whether there was video of the shootings.

The attacks on police this summer in Dallas and Baton Rouge came in the wake of several high-profile police shootings of black men, fuelling a national debate about police use of force, especially against minorities. This was also a frequent topic during the US presidential race.

Republican nominee Donald Trump has argued that police need the freedom to use greater force, while Democrat Hillary Clinton has taken a more nuanced position of supporting officers while also calling for restraint when dealing with minority communities.

The most divisive US general election in memory is just six days away.

State governor Terry Branstad called the killings "an attack on the public safety of all Iowans".

He added: "We call on Iowans to support our law enforcement officials in bringing this suspect to justice. Our thoughts and prayers go out to the families of the police officers who were tragically killed in the line of duty as well as the officers who continue to put themselves in harm's way."

Urbandale is a suburb of about 40,000 people in the Des Moines metro area, with about 50 officers. Authorities have closed local schools for the day.

Des Moines has about 375 sworn officers.