Two persons were burnt and injured after unidentified arsonists set a bus on fire in Dhaka's Meradia this morning.

Following the arson attack around 7:30am at Bashpattali area, the driver of the Achhim Paribahan lost control and hit a roadside tree, police and the injured said.

The injured are Md Sabuj, a driver of Ramjan Paribahan who was travelling to Meradia from Badda on the Achhim Paribahan bus, and its helper Sabbir Hossain.

Sabuz has been receiving treatment at Sheikh Hasina National Institute of Brun and Plastic Surgery with 28 percent burn on his body

"His condition is critical as he had burns on the respiratory tract," a doctor of the institute said.

Sabbir was taken to NITOR as he suffered injuries in the leg alongside minor burns, police said.

Monir Hossain Mollah, officer-in-charge of Khilgaon Police Station, said two persons were injured after unidentified persons set the bus on fire.

Police are investigating the incident, he said.

Lima Khanam, duty officer of Fire Service and Civil Defence, said they were first informed by locals about the fire.

"We did not need to work on the spot as locals doused it and informed fire officials minutes later," she said.

Today is the first day of a two-day blockade called by BNP and Jamaat-e-Islami.