In Pakistan, five persons were killed and 18 others injured when a roadside bomb hit a bus carrying navy personnel in Karachi on Thursday. A Pak navy spokesman said the blast killed four navy employees and a civilian.It was the third such attack this week in the southern port city, which is the main base for Pakistan's navy.The Taliban has claimed responsibility for the bombings on Tuesday that also targeted buses carrying navy personnel.Those attacks had killed four people and wounded more than 50 others. The attacks come days after Pakistan's army chief said his forces have broken the back of insurgents linked to the Taliban and al-Qaida.