In a landmark judgement, the National Green Tribunal Bench in Kerala today banned light and heavy diesel vehicles, which are more than 10 years old, in six major cities. These are state capital Thiruvananthapuram, Kochi, Kollam, Thrissur, Kozhikode and Kannur. <br/><br/>In its first sitting, the bench, comprising NGT chairperson also directed the state government not to register any diesel vehicle in the capacity of 2000 CC and more, except public transport and local authority vehicles. The bench issued the order while hearing a petition seeking action against highly polluting diesel vehicles such as trucks and buses.