Seven people were injured in a fracas involving supporters of Delhi legislator Shoaib Iqbal and another group over digging work for laying a water pipeline in central Delhi, police said, adding that the law maker's personal security officer (PSO) had to fire in the air to disperse the crowd.

"The incident was reported around 2.30 p.m. when work of laying a water pipeline was to take place in Sitaram Bazar from the constituency fund of Iqbal," a police official said.

"Some locals, who were against the laying of pipelines, got into an argument with the legislator and objected to the inauguration of the project," the official said.

The argument turned violent and seven people were injured.

In order to bring the situation under control, Delhi Police head constable Gopi Chand, who is also the PSO of the legislator from Matia Mahal constituency, fired three bullets in the air.