The Department of Environment (DoE) filed cases against 11 vehicles, including bus, mini-bus and cab, in the city yesterday for causing noise pollution. The cases were filed under Motor Vehicle Ordinance-1983 during a drive at Old Airport Road on the second day of the DoE's four-day awareness campaign against noise pollution. A team led by DoE Deputy Director (implementation) Billal Hossain conducted the drive. BRTA representatives and policemen were on the team. The team also seized two hydraulic horns and distributed leaflets. After Ramadan, a massive drive will be launched and action will be taken against those who will violate Noise Pollution (control) Rules-2006, the DoE official said, adding that the rules does not allow people to use horns that produces sound over 85 decibels on the main thoroughfares. There is a restriction on using horns near the educational institutes and hospitals, but the people continue to violate the rules as they are not aware of it, he said.