PIA AT42 at Karachi on Nov 28th 2013, unsafe gear after departure

A PIA Pakistan International Airlines Avions de Transport Regional ATR-42-500, registration AP-BHI performing flight PK-550 from Karachi to Multan (Pakistan), was climbing out of Karachi when the crew stopped the climb at 6000 feet due to an unsafe gear indication and returned to Karachi for a safe landing about one hour after departure.