Three Hizbul Mujahideen Over-Ground Workers have been arrested for their involvement in a grenade attack in Kupwara district of Kashmir in November 2011, the police said on Tuesday.

"The police has solved a militancy case pertaining to a grenade attack on a (security) bunker at General bus stand in Kupwara on November one, 2011 by arresting the kingpin of the assailants, Javid Ahmad Shah, an OGW of Hizbul Mujahideen," a police spokesman said.

During interrogation, Shah confessed of his involvement and also revealed the names of two others involved in the case -- Mohammad Abdullah Bhat and Nawaz Ahmad Shah.

The other two accused, who were also working as OGWs for the terrorists, have also been arrested, he added. Three pedestrians including a woman had sustained splinter injuries in the grenade explosion.