Police officers and rescue workers inspect damages after a car bomb exploded outside a police accommodation in Narathiwat town, southern Thailand on November 22, 2022. One person died and more than two dozen were injured in the attack, the provincial governor said. Photo: AFP

 Thai military frigates and helicopters were on Monday searching for 31 sailors after a naval vessel sank, with dozens of others having been hauled from choppy waters.

The HTMS Sukhothai capsized late on Sunday night as it was patrolling the Gulf of Thailand, about 37 kilometers off the nation's southeastern coast.

Some sailors survived by jumping into a life raft at night, according to images shared by the Royal Thai Navy, which said 75 people had been rescued.

However, 31 sailors were still missing on Monday afternoon, according to navy spokesperson Admiral Pogkrong Montradpalin. The search and rescue operation involved two Seahawk helicopters, two frigates and one amphibious ship, according to a navy statement.

Prime Minister Prayut Chan-o-Cha said the cause of the incident was being investigated. "I am following the news closely, about five people are seriously injured," he added in a statement.

The navy spokesperson said the vessel sank after its electronics system was damaged. "The ship's operating systems stopped working, causing the ship to lose control," he said.

One image shared by the navy showed the vessel capsized, while a video showed a rescue boat alongside the ship in rough waters. Other images showed men wrapped in blankets following their rescue.

Several areas in southern Thailand have been hit by storms and flooding in recent days. The HTMS Sukhothai was commissioned in 1987.

In 2018, a boat carrying tourists capsized off Phuket island on Thailand's west coast. Over 40 people died in the accident, one of the worst boat disasters in the country's recent history.

AFP