Malaysia's coast guard has held training under the guidance of its Japanese counterpart to better deal with foreign ships in the South China Sea, where Beijing is ramping up its maritime activities.

The exercise took place in waters off the island of Borneo on Thursday. It was a project of the Japan International Cooperation Agency, or JICA, to enhance Malaysia's capabilities to ensure maritime security.

The drill involved a Malaysian patrol ship equipped with a long-range acoustic device that can send audio over long distances.

Its crew warned fishing boats acting as intruders in Malaysia's exclusive economic zone and ordered them to leave the waters.

Japan is expected to provide four of the acoustic devices to Malaysia.

Chinese vessels have been increasing their activities in the South China Sea. Vietnamese fishing boats have also been more frequently spotted operating illegally in the waters.