Transport bosses have hit out at yobs who smashed the windows of four buses.
As previously reported, an investigation is under way after stones were thrown at the vehicles in the Nel Pan Lane area of Westleigh.
Three of the buses were targeted on the same night, while one was damaged a week earlier.
Now, Transport for Greater Manchester, which co-ordinates public transport in the region, has condemned the incidents.
A spokesman said: "This recent spate of vandalism against buses is completely unacceptable.
"Quite aside from the traumatic impact on bus passengers and drivers, this has also led to damaged vehicles being withdrawn from service – inconveniencing people who need to travel locally and at a cost to the bus operators.
"Our first and foremost concern is driver and passenger safety and the Greater Manchester Travelsafe Unit will be investigating these incidents and working in the area to tackle the problem.
"Any offenders identified will be prosecuted.
Three windows were smashed when stones were thrown at a Jim Stones bus travelling along Nel Pan Lane at 5.15pm on Tuesday, November 15.
Repairs cost £1,000 and the bus, which had only been operating for two days, had to be taken off the road.
There have been reports of three further incidents in the area between 9pm and 10.30pm on Thursday, November 24, when the windows were smashed on three buses.
Two of the buses were travelling along Nel Pan Lane and another was on nearby Leigh Road.
It is understood that stones have also been thrown at other passing vehicles and houses.
No-one has been hurt in the incidents, but fears have been raised that someone could be injured or even killed if the vandalism continues.
A bus company in Dundee became so fed up with its vehicles' being attacked that it teamed up with the local council and emergency services to make a public information film earlier this year. It shows a double-decker targeted by a youth who throws a brick, breaking the window and injuring passengers. The bus then swerves towards a young mum pushing a buggy.