(Adds details of assault and Taliban claim of responsibility)
JALALABAD, Afghanistan, March 20 (Reuters) - Taliban fighters killed at least four people and wounded 20 in a suicide car bomb attack and gunbattle at a police station in Afghanistan's eastern Jalalabad city early on Thursday morning, according to police and health officials.
The attack started just before dawn, and a firefight raged for more than three hours after the initial explosion. Police reckoned around half a dozen fighters were involved in the assault. Most had been killed, but the police were unsure exactly how many fighters were still holding out.
"Five suicide bombers have been killed so far and a clearance operation is ongoing," said police spokesman Hazrat Hussain Mashriqiwal.
The Taliban sent a text message to media claiming responsibility for the attack on the police station, located close to compounds used by international agencies, including the United Nations, security officials said.
Security forces discovered at least two roadside bombs on the heavily guarded highway between Jalalabad and Kabul on Wednesday, and carried out controlled explosions.
(Reporting by Rafiq Shirzad in Jalalabad and Mirwais Harooni and Jessica Donati in Kabul; Editing by Simon Cameron-Moore)