Used diesel car owners in Seoul must install a diesel particulate filter beginning in the latter half of the year under a new regulation to improve air quality, city officials said Monday.

Those caught without the device will be fined 200,000 won ($175).

Diesel vehicles such as vans, buses and trucks that weigh more than 3.5 tons and have been used more than seven years are subject to the new rule.

The vehicles will be monitored through closed circuit television cameras on the streets of the capital as well as neighboring cities.

“We notified owners of diesel vehicles to install the filter in March. We are giving them time to install the filter before we begin to sort out the uninstalled ones in the second half of the year,” said an official of the environment and transportation division.

The city government supports 90 percent of the cost spent on placing the filter and exempts them from future charges for environmental burden reduction and vehicle exhaust emission checkup.

By Lee Woo-young (wylee@heraldcorp.com)