BSF officials said the first incident took place at Naushera Dhalla village of Amritsar sector in the wee hours.
According to them, troops deployed at a border outpost observed some suspicious movement along the fence. Sensing that a gang was trying to smuggle in some goods, the troops challenged the smugglers to stop.
But the smugglers opened fire, drawing retaliation from the BSF troops, officials said. However, taking advantage of dense fog, the smugglers managed to flee.
Meanwhile, 16 packets (1 kg each) of heroin were seized from the Ferozepur sector, along with a pistol, one magazine and six round of ammunition, BSF officials said.