Mohammad Sohrab, 28, Mohammad Amirul Islam, 29, Alamgir, 27, Mohammad Anisur Rahman, 30, Anwar Hossain, 28, Mizan, 29, and Abdul Barek, 30, were arrested with a pipegun and a cartridge, police said.

Tipped-off, the police team approached to search a Gabtoli-bound bus (Dhaka Metro Ja-5072) in front of Prince Plaza at Sobhanbagh at about 1:45am but it speeded up to dodge police, said MA Malek, officer-in-charge of Mohammadpur Police Station.

"We chased the passenger bus and asked all police stations to stop it as its movement raised suspicion among us," he added.

Despite the alert, Tejgaon and Ramna police failed to stop the vehicle at different city points.

Motijheel police put up a roadblock in the Danik Bangla intersection as Mohammadpur police were chasing the bus down. However, the bus took a U-turn in a last-ditch evasive action but could not go far off, Malek added.

Barek jumped from the bus during the chase and was admitted to Dhaka Medical College Hospital with head injuries.

During preliminary quizzing, the alleged robbers said they looted buses and other vehicles at various points between Gabtali and Gulistan and on several highways, Malek said.

Two cases were lodged with Mohammadpur Police Station.