Four armed miscreants, with their faces masked, tied up the residents of an apartment and escaped with cash and jewellery worth Rs four lakhs at Bishnupur in the southern fringes of the city on Friday night. The miscreants scaled the backside wall of the apartment, climbed the roof and broke open the gate on the roof. They threatened one of the five family members at gunpoint and tied all of them up. They rummaged all the six almirahs and looted everything. Cops suspect the involvement of a professional gang in the incident. The CCTV footage of the apartment is being scanned for leads.