The number of traffic accidents occurring while drivers were using mobile phones declined 52.1 percent in the 11-month period to the end of September from a year earlier to 928, the National Police Agency said Thursday.

The fall "reflects stepped-up efforts by police to crack down on those using mobile phones, following the implementation of the revised Road Traffic Law last November," an agency official said.

Under the revised law, drivers are fined if caught using a hand-held mobile phone -- whether talking, text messaging or reading the screen -- while driving. Use of hands-free phones is permitted under the law.

Drivers of small motorcycles who violate the law are fined 5,000 yen. Violators driving cars and large motorcycles must pay 6,000 yen and those driving large vehicles, including trucks and buses, must pay 7,000 yen.

Those who refuse to pay can be fined up to 50,000 yen.

The NPA report also said a total of 441,600 drivers were arrested or referred to prosecutors for using mobile phones while driving.