Taliban fighters tried to overrun a provincial capital in Afghanistan early on Friday, hiding inside homes before slipping into city streets in the night to attack security forces and killing at least 14 policemen before being pushed back, officials said. The overnight attack in the southeastern city of Ghazni, the capital of a province with the same name, also wounded at least 20 members of the security forces, said Baz Mohammad Hemat, the administrator of the Ghazni city hospital.

The city was in lockdown and fighting continued throughout most of the day Friday, with sporadic bursts of gunfire from Taliban fighters who had hunkered down in elevated positions inside Ghazni from which they were shooting, some residents said, speaking on condition of anonymity for fear for their safety.

An Afghan military helicopter crash landed in the city during the daytime fighting, and four Afghan soldiers on board were injured, one critically, said Mohammad Radmanish, spokesman for the Ministry of Defense. He said it was not clear if the helicopter had been hit. Elsewhere in Afghanistan, a Taliban attack Thursday night in western Herat province left six policemen dead in the district of Obe, said the governor's spokesman there, Gelani Farhad. The brazen assaults by the Taliban underscore the difficulties Afghan forces face in battling the relentless insurgency on their own in efforts to end the nearly 17-year war.