KABUL, September 27 (RIA Novosti) - At least four people have been killed and another 17 injured in a suicide blast targeting Afghanistan's energy minister in western Afghanistan, a police spokesman said on Sunday.

Energy and Water Minister Mohammad Ismail Khan was not hurt after a suicide bomber blew himself up on the main road to the airport in Herat on Sunday, Raouf Ahmedi said.

The radical Islamic Taliban group claimed responsibility for the attack on Khan, a key member of the Northern Alliance whose forces helped U.S. troops in overthrowing the Taliban regime in 2001.

Violence has surged in Afghanistan in the past few years, with the radical Islamic Taliban group staging regular attacks on provincial government officials, police and troops.