Seven Filipino fishing boats were seized after being caught intruding into Malaysian waters off Pulau Balambangan, maritime authorities said.

The boats were detected near Tanjung Kalutan using Sabah’s sea surveillance system, triggering a rapid response by patrol vessels from the Kudat Maritime Zone.

All seven vessels were stopped, with officers finding 21 people on board, including skippers aged between 17 and 60.

The boats and crew were escorted to the vessel detention centre at Sabah Port in Kudat for further investigation. The haul is estimated to be worth RM100,000.

Authorities said the case is being probed under fisheries laws for entering Malaysian waters without permission, as well as immigration laws after those detained failed to produce valid identification documents.

Maritime officials warned there would be no compromise on illegal intrusions and said patrols would be stepped up in high-risk waters.

The public has been urged to report suspicious activity at sea to maritime authorities or through the emergency hotline.