The blasts took place at around 9:30 pm last night at Hotel Orchard, a 12-floor building in central Dhaka.
A Sri Lankan national was badly injured when the first blast went off, they said, adding two more loud explosions within two hours rocked the two-star hotel.
Police official suspects the blasts were caused by a leak in a gas pipeline.
Fire and explosives experts were at the scene to investigate. No arrests have been made so far, they added.