GUWAHATI/AIZAWL/ITANAGAR/SHILLONG/DIBRUGARH: The Republic Day was celebrated peacefully across the northeast on Friday despite boycott calls made by militants. "Republic Day was celebrated peacefully across Mizoram without any untoward incident. Outsourcing such attacks is not new to Ulfa (I) who want to make their presence felt every now and then. Assam Police on Saturday said Ulfa (Independent) was behind the blasts and they had carried out the attacks with the help of 'hired hands'. "Ulfa (I) outsourced the job of planting bombs to a few local sympathisers..