A residential community has been hit by stray bullets from an armed police training center only 300 meters away, Shanghai police said.

Residents said the "mysterious bullet attacks" started about five years ago, and while not frequent, were scary and dangerous.

"Sometimes the whole place sounds like a battlefield and we have somehow gotten used to it," said Zhou Weiming, a 50-year-old resident. "But it's not funny when you come to the parking lot and see a bullet lying near your car."

The stray bullets have penetrated windows and also been found near cars, according to residents.

Baoshan police said most of these bullets were fired from handguns or automatic rifles by armed police officers during target practice at a man-made hill at a nearby training center on Tonghe Road.

Officers said some of the bullets ricocheted off hard rocks and then hit homes in the community.

The latest incident occurred at 7pm on Monday when a woman surnamed Xu said she was terrified after a 5 millimeter bullet penetrated her bedroom window, which is on the eighth floor of a residential building on Yi'erba Jinian Road.

Zhou said at least five residents have been shocked after bullets hit their homes over the past five years.

Zhou said two years ago a handgun bullet penetrated the window of his bedroom on the 11th floor and it was later found stuck in the floor.

Several days after he reported the case to police, a group of armed police visited his apartment and offered him two watermelons to apologize. The armed police officers said the bullets were fired during training and had changed direction after hitting some hard rocks, according to Zhou.

Zhou said he refused the watermelons as the men said it would be difficult to relocate the training ground.

An official surnamed Su with the property management company said the neighborhood committee has complained to the training center several times, but nothing has changed.

Su tried to reassure residents that the bullets traveled at slower speeds after ricocheting off rocks.

Some residents said they blame the property developer for building a residential area even though it knew of the possible dangers posed by the training center.