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 US-led invasion that ousted the Islamic militant movement following the September 11 terror attacks.
President Hamid Karzai is constitutionally barred from seeking a third term.
In today'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 Mohammad Ayub Salangi said.
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 casualties.
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.
