At 10 a.m. on Monday this week, Lieutenant-Colonel Ali Khalaf says the police department in the Iraqi town of Ramadi issued an order for him to return to the force after eight months out of work.

At 1:45 p.m. the same day, a bomb detonated remotely tore through his kitchen wall, killing his 20-year-old nephew, also a police officer.

Fifteen minutes later, a second device rigged to a washing machine timer exploded outside the house.

Khalaf needed no further proof of the threat posed to the Iraqi security forces by a diminished but adapting insurgency, or the corrupt police officers that feed it.

“Now I will try to get passports for me and my family and we will leave Iraq,” he said by telephone from Ramadi, 100 km (60 miles) west of Baghdad.

Four bombs exploded that day outside the homes of three police officers in Ramadi, capital of Anbar province — once a hotbed of Sunni Islamist insurgents like al Qaeda.

Khalaf’s nephew, his head crushed and one arm ripped off by the blast, was the latest victim in a wave of targeted killings now the modus operandi of the insurgency.

Overall violence in Iraq has dropped sharply since the sectarian slaughter of 2006-07. The insurgency unleashed by the 2003 U.S. invasion remains entrenched in some areas, and bombings are still a regular occurrence.

But in recent months, large scale bombings — the trademark of al Qaeda in Iraq — have given way to cold assassination.

Police officers, churned out of academies as frontline forces, are a favourite target, alongside tribal leaders, government officials and former Sunni insurgents who switched sides and helped turn the tide of the sectarian war.

Sunni insurgents see the police as traitors in league with the U.S. military and Iraq’s Shi’ite majority, dominant since the overthrow of Sunni dictator Saddam Hussein.

“This isn’t over yet,” Lieutenant-General Michael Barbero, NATO’s Iraq training commander, said this week at the graduation of some 700 Italian-trained federal police outside Baghdad.

“Al Qaeda and others are crippled and damaged but they’re still viable and still can conduct these attacks, whether its high-profile attacks or acts of intimidation,” he told Reuters.

CORRUPTION, COLLUSION

Since February, more than 100 people have been killed in targeted hits, quietly executed by gunmen equipped with silencers, many of them homemade, or blown up in their cars by small bombs attached by adhesives or magnets.

Khalaf’s case underscores one of the key challenges facing Iraq’s security forces as U.S. troops prepare to end combat operations in August and cut numbers to 50,000 from the current 94,000 by Sept. 1.

The police now number some 400,000, and the army, navy and airforce around 250,000, according to the U.S. military.

In 2007 Khalaf says he joined other members of his community in Ramadi in taking up arms against al Qaeda insurgents, and was eventually given the rank of lieutenant-colonel by U.S. forces.

He says he was kicked out eight months ago by former officers under Saddam Hussein who returned to work with the improved security situation.

Then last week, he was called back by a colonel in need of experienced fighters. Then he received a text message on his mobile phone that read: “Our swords are thirsty for your blood.”

Then came the bombs. Khalaf says police corruption and collusion with insurgents runs deep.

On Monday, a police officer in the town of Samarra, 100 km (60 miles) north of Baghdad, was sentenced to 15 years in prison for leaking information about fellow officers to al Qaeda.

On Tuesday, a number of senior police officers in Baghdad’s Bayaa district were arrested in connection with a brazen gold heist in an otherwise heavily-guarded shopping street in which 14 people died.

“There are many police officers and local officials cooperating with al Qaeda,” said Khalaf.

“Their aim is to target innocent people, those who fought al Qaeda before, and to stop them from returning to work.”

Asked about Khalaf’s case, LTG Barbero said the U.S. was helping the Interior Ministry in “vetting” recruits, adding:

“The lesson I take from that is we must maintain pressure on the (insurgent) networks.”

But Khalaf said he no longer knew whom to trust.

“I must find safe shelter for us. I will come back when innocent people reappear and they are ready to join hands with us to walk together.”

(Writing by Matt Robinson; Editing by Samia Nakhoul)