"Unidentified assailants opened fire at a vehicle in which four people were traveling in Hayatabad Phase I,” a police official told“They belonged to the Shia Muslim community and it appears to be a sectarian attack,” the official added.In February, heavily armed militants stormed a Shia mosque in Hayatabad killing at least 19 people in an attack claimed by the Taliban as revenge for the execution of one of their cadres.Three attackers with grenades, Kalashnikovs and explosive suicide vests struck at the Imamia mosque at the time of the main Friday prayers.