JALALABAD, Afghanistan -- A suicide car bomber blew up his vehicle near a police station in eastern Afghanistan while other Taliban insurgents stormed the building Thursday, killing 10 police officers and a civilian, officials said.
The brazen assault in Jalalabad, an economic hub near the border with Pakistan, comes as the Taliban have threatened to use violence to disrupt April 5 elections for a new president and provincial councils.
The vote will be the first democratic transfer of power since the 2001 U.S.-led invasion that ousted the Islamic militant movement following the Sept. 11 terror attacks. President Hamid Karzai is constitutionally barred from seeking a third term.
His successor will guide the country as international forces wind down their combat mission by the end of this year.
In Thursday's Jalalabad attack, the suicide bomber blew up his explosives-laden car before dawn outside the police station, located near the palatial residence of the governor of Nangarhar province, Attaullah Ludin.
Six gunmen then rushed into the station as two more bombs exploded nearby -- one hidden in a motorized rickshaw and another in a vegetable cart.
That prompted a fierce battle that lasted more than four hours, with Afghan police fighting their way out and chasing gunmen down the street. All seven attackers were killed, deputy Interior Minister Gen. Mohammad Ayub Salangi said.
Police said the 11 killed included a city district police chief and a university student caught in the crossfire.
The Interior Ministry said 15 policemen also were wounded in the attack, which it said was aimed at sabotaging the upcoming elections.
Taliban spokesman Zabihullah Mujahid claimed responsibility for the assault, saying the attackers wore suicide vests and that nearly 30 policemen were killed. The Islamic militant group frequently exaggerates casualty figures.
The nearby state-run Afghan radio and television building was badly damaged in the initial suicide bombing.
The Taliban have carried out numerous attacks in Jalalabad and elsewhere in the east, which along with southern Afghanistan is their traditional stronghold.
Afghanistan has released dozens of prisoners who had been held by foreign troops despite warnings by the Americans that many of the men are dangerous and likely to return to the insurgency.
On Thursday, dozens more prisoners -- including some 40 who had been detained by British forces in the southern Helmand province -- were freed by the Afghan panel that reviews cases from the Parwan detention center, officials said.
British Embassy spokesman Maj. Tim James says Britain disagreed with Thursday's release but "has to respect it because it is an Afghan decision."
James declined to discuss specific charges facing the men, saying only that "we believed that we had enough evidence against these individuals to merit them going into the Afghan judicial system."
James said 77 were released -- of which 39 were former British detainees.
Abdul Shakoor Dadras, a member of the Afghan review panel, said 55 were released Thursday, including 40 who had been held by British forces. Dadras said the men were released for a lack of evidence and that 48 other cases have yet to be decided.