HERAT, Afghanistan - A roadside bomb targeting an Afghan cabinet minister exploded in the western city of Herat on Sunday, killing at least three people, officials said.

Energy and Water Minister Mohammad Ismail Khan, a prominent anti-Taliban commander, was not hurt, police said.

The Taliban claimed responsibility for the attack on Khan, a key member of the Northern Alliance whose forces helped U.S. forces in toppling the Taliban in 2001.

"The target was Ismail Khan," Zabihullah Mujahid, a Taliban spokesman, told Reuters by telephone from an undisclosed location.

The explosion occurred outside a school in Herat, killing three people and wounding 16, residents and a doctor said.

Police in Kabul said Khan survived the attack unscathed.

"He was on his way to Kabul and is fine," a police source in Kabul said. "But civilians have been killed."

(Reporting by Sharafuddin Sharafyar and Sayed Salahuddin; Editing by Maria Golovnina)