KABUL: At least 20 policemen were killed Monday when a suicide bomber struck a police base in Kabul Monday.

Scores of people were also wounded as the attacker blew himself up in a queue of police officers waiting to enter the base, leaving several bodies and charred debris strewn around the area.

The carnage marks one of the worst attacks on Afghan forces in recent months, despite a renewed push international push to restart formal peace talks which stalled last year.

“As a result of the terrorist attack near the Afghan National Civil Order Police headquarters... 20 people were martyred and 29 others were wounded,” the interior ministry said in a statement.

A senior ministry source told AFP that all of those killed were policemen, and at least three critically wounded officers were battling for their lives in hospital.

The health ministry said some of those wounded were hit in the chest by flying shrapnel.

Ambulances rushed to the scene, which was cordoned off by authorities after the bombing which comes amid the Taliban's unprecedented winter offensive.

The Taliban claimed responsibility for the attack, with insurgent spokesman Zabihullah Mujahid claiming on Twitter that up to 40 police were killed and wounded.

The attack comes just ahead of a third round of four-country “roadmap talks” trying to lay the groundwork for direct dialogue between Kabul and the Taliban.

Delegates from Afghanistan, Pakistan, China and the United States are set to convene in Islamabad on February 6 in a bid to seek a negotiated end to the 14-year Taliban insurgency.

The Taliban have stepped up attacks on government and foreign targets in Afghanistan this winter, when fighting usually abates, underscoring a worsening security situation.

Observers say the intensifying insurgency highlights a push by the militants to seize more territory in an attempt to wrangle greater concessions during talks.

Kabul in blackout as govt struggles to fix power lines

Militants and bad weather in northern Afghanistan have hampered efforts to repair power lines that were destroyed last week, cutting electricity in the capital, Kabul, to about six hours a day, officials said on Monday.

Insurgents last week destroyed an electricity pylon in the Dand Shahabuddin district of Baghlan province that brought power from Uzbekistan to meet almost half of Kabul's 600 megawatt daily requirement.

Mirwais Alami, chief commercial officer at Afghanistan's national power company, said repair crews had been unable to get close to the power lines because of mines and the threat from insurgents and said residents reported that more pylons had been brought down.

“Enemy forces have brought machine saws and have been cutting down electricity pylons,” he said.

The Taliban has denied being responsible for bringing down the power lines, saying such tactics, which hit ordinary people, do not fit with their fight against the foreign-backed government.

The destruction of the power lines has hit businesses and industry and added further misery for Kabul's long-suffering residents, already tested by a series of suicide bomb attacks this year.

For the well-off with private generators, the cuts have meant higher fuel bills but for those who rely on the public grid, they have meant dark nights and reliance on wood-burning stoves to fight the winter cold.

Abdul Satar Barez, the provincial governor of Baghlan, said operations to secure the area in order to allow repair crews to work on the pylons had been suspended due to fog and bad weather.

“Taliban are still in the area, they are a threat and danger and we cannot launch our operation now. We are waiting for the weather to get better,” he said.