BEIJING, March 13 -- A Beijing power plant operated by one of China's leading power producers caught fire on Friday afternoon, with no casualties reported so far.

Local police said their helicopters noticed smoke coming from China Huaneng Group's Beijing Thermal Power Plant in Chaoyang District during routine patrol at around 2:50 p.m. They dispatched rescuers and 91 fire engines to the site.

A statement on the company's official website said the fire had been put out and an investigation has been launched.

A Fortune 500 company, the group said it owned or held majority stakes in power plants both home and aborad, with a combined capacity of 143 million kw by the end of 2013.

The fire started at the No.2 generating unit of the plant, leading to the shutdown of all the four units, according to the group's website.

The plant was put into operation in 1999.