One of the country's most wanted men has given himself up to police after two unarmed female officers were killed attending a "routine incident".
Eyewitnesses said a hail of bullets was fired and a grenade was thrown during the attack in Hattersley, Greater Manchester. One of the officers died at the scene. The second was critically injured and died later.
Soon after the attack, Dale Cregan, 29, who was being hunted in connection with separate gun and grenade attacks that killed a father and son, walked into a nearby police station.
Assistant Chief Constable Garry Shewan said: "A long and dark shadow has been cast across Greater Manchester and my thoughts are with the officers' family, friends and colleagues."
Cregan, who only has one eye, had been the subject of a huge manhunt after the murders of David Short, 46, and his son Mark, 23. A £50,000 reward had been offered for information leading to his arrest.
Police said the two officers had been attending an incident at Abbey Gardens in Hattersley, Tameside. The force did not give any details of the incident but described it as "routine".
Local window cleaner Warren Shepherd was on his rounds close to where the officers were shot.
"I just heard gun shots, bang, bang, bang - around 10 of them, then a pause and a big explosion," he said.
"I went around the back of the houses to see what happened and there was a police car that looked empty. There was people, neighbours stood around there and one of my customers said, 'They've been shot! The police officers have been shot!'"
Prime Minister David Cameron said that the killing of two police officers in Manchester was "a shocking reminder of the debt we owe to those who put themselves in danger to keep us safe and secure".