Jaffarabad- At least four people were injured when militants hurled a hand grenade at a shop in Balochistan's Jaffarabad district today, the police said. Muhammad Ayub, a police official, told a private TV channel that two militants riding on a motorcycle hurled a hand grenade at a shop in Jaffarabad's Osta Mohammad tehsil. He said four people sitting inside the shop were injured. "The blast also damaged the shop," Ayub said. He said the injured were rushed to Osta Mohammad hospital for medical treatment. "This was a targeted attack," he added. The glasses of nearby shops were also smashed. The militants sped away on their motorcycle after the attack. There was no immediate claim of responsibility for the attack. However, Ayub suspected Baloch separatists could be behind the attack. Militants in Jaffarabad district have been targeting security forces and vital national installations for more than seven years.