At least seven persons were killed and several others injured in Karachi on Friday when a blast ripped through a house where explosives and weapons were stored. The blast in Baldia Town area of the port city appeared to be accidental.<br/><br/>Police said, Bomb disposal squad personnel were trying to determine its exact nature. Two Kalashnikov assault rifles, 22 grenades and two suicide jackets were found in the one-room house, which collapsed due to the explosion.<br/><br/>The explosion blew out the windows of several homes in the congested neighbourhood. Pakistan Interior Minister Rehman Malik told reporters in Islamabad that the home had been rented by a man from the militancy-affected Swat valley.<br/><br/>He said, some persons from Swat had come to visit this man last night, Police officials said Riaz Khan, who hailed from Swat, had rented the house about two years ago.<br/><br/>Two grenades were found in the pocket of one of the dead. Karachi police Chief Waseem Ahmed said the men living in the house could have been planning a terrorist attack.<br/>