A bomb killed one person and injured at least 50 others when it exploded on Saturday in the parking lot of a Bangladesh hotel where Sylhet city's opposition-backed mayor had just held a meeting, witnesses and doctors said.
The explosion occurred two days after blasts outside two cinemas in the town, 300km from Dhaka, killed one man and wounded 15.
A leader of the main opposition Awami League party was among those hurt in the blast, witnesses said.
Some 25 people were taken to hospital, doctors said.
Police said the bomb was packed with shards of metal. They did not immediately know who was behind the attack or what the motive was.
Hundreds of opposition activists staged a noisy protest, demanding those responsible be punished.
A bomb blast at a mosque in Sylhet in May wounded more than 50 people, including the British High Commissioner in Bangladesh.