At least 11 Afghan police officers have been killed after Taliban fighters stormed a police base in Pul-e Khumri, the capital of Baghlan province, local government officials told the Associated Press on Tuesday.

The fighters first overran a checkpoint near the base late on Monday and were apparently able to breach the compound with ease because a sympathetic policeman opened a door for them.

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Details were provided by Mahbobullah Ghafari, a Baghlan provincial councilman. A local police official, speaking on condition of anonymity because he was not allowed to brief reporters about the attack, also gave the same account.

Six others were wounded in the overnight attack in Pul-e Khumri, provincial council member Samiuddin Nazir told DPA news agency.

A spokesman for the Taliban, Zabiullah Mujahid, however, put the death toll at 17, adding that one officer was taken hostage. The group has, at times, exaggerated its claims.

The attack comes one day after the Taliban claimed it shot down an American military plane in Ghazni province - a claim the US military denies.

Frequent attacks

Insider attacks have been steady throughout Afghanistan's 18-year conflict, with US and NATO troops the most frequent targets.

Last July, two US service members were killed by an Afghan soldier in the southern province of Kandahar. The shooter was wounded and arrested. In September, three US military personnel were wounded when a member of the Afghan Civil Order Police fired on a military convoy, also in Kandahar.

The Taliban have a strong presence in Baghlan, one of the most troubled provinces in Afghanistan last year, and frequently target Afghan security forces in and around the capital.

Last September, Taliban fighters attacked Pul-e Khumri city in a bid to overrun it and were driven out by security forces only days later.

The Taliban currently control or hold sway over approximately half the country.

The US and the Taliban are currently attempting to negotiate a reduction in hostilities or a ceasefire. That would allow a peace agreement to be signed that could lead to the withdrawal of US troops and open the way to a broader post-war deal for Afghans.