A group of alleged local terrorists attacked workers demanding extortion in Chandmia Residential Area of the city yesterday. In the attack a construction workers received bullet injury and was admitted to Chittagong Medical College Hospital (CMCH) in a critical condition, said police sources. The bullet injured worker was identified as Mohammad Mahfuz, 22, from Mehidiganj of Rangpur district. Chandagaon police sources said that a man Mohmmad Nasir is constructing a building at Chandmia Residential Area. After starting the construction work, a group of local youths who are known as follower of local identified terrorist Arman were demanding extortion.  While the labours starting their work, a group of people came to the spot and demanded extortion as like as past. Without getting extortion they attacked the labours, said the police sources.