A train running on Shanghai's Metro Line 11 hit an arm of a tower crane that had fallen onto the track on Sunday morning, causing a delay in service, the city's metro operator said, adding that no one was injured in the incident.

The incident occurred at around 8 am on an aboveground section of the line between Malu and Wuwei Road stations. Shanghai Metro said a construction project involving a tower crane had invaded the metro line, damaging the train and other metro facilities.

It apologized for the service delay and said repairing the facilities would take some time. Services in five affected stations were suspended, while the rest of the line remained operational. Five bus routes were arranged to transport affected people.

A witness told local media Xinmin Evening News that the train came to an emergency stop after a huge bang. Some windows near the front of the train were shattered, and passengers had to walk on foot on a path next to the track to the nearest station, the witness said.

China's Ministry of Emergency Management contacted local fire and rescue squads and first responders and sent a working group to the site to oversee their efforts. It also required related industries in the city to conduct safety checks, analyze the cause of the incident and punish those responsible.