Jakarta, Feb. 11 -- Four people have died, and three others are missing after a speedboat carrying 51 passengers capsized in Indonesia's North Kalimantan province, a senior rescuer said on Tuesday.

The speedboat, Iksa Express, was struck by large waves and overturned while passing through waters off Bulungan Regency on Monday, according to Dede Hariana, head of the operational units at the provincial search and rescue office.

"Four people lost their lives in the incident. Three others are still missing, and search efforts are ongoing. There were 51 people on board at the time of the accident," Hariana told Xinhua via phone.

He explained that the speedboat was hit by massive waves, leading to the fatal maritime incident.

Rescuers eva...