Malaysian maritime authorities were searching Tuesday for 14 Indonesians still missing after a boat believed to be carrying undocumented migrants sank in waters off the coast of Perak state, the regional maritime office said in a statement.

The boat capsized near Pangkor Island, roughly halfway up the west coast of peninsular Malaysia. A fishing vessel that encountered survivors floating at sea before dawn on Monday raised the alarm. Twenty-three people were pulled from the water and later handed over to marine authorities for questioning, Perak maritime chief Capt. Mohamad Shukri Khotob said. He told the Associated Press that 37 people were believed to have been aboard.

The search and rescue operation, which began Monday, would continue until all missing individuals were located, the statement said. Authorities did not describe the condition of the survivors in detail.

Mohamad Shukri said the group had departed three days earlier from Kisaran, a port town in Indonesia’s North Sumatra province on the Strait of Malacca. Their intended destinations included Penang, Selangor, and Kuala Lumpur — territories spread across Malaysia’s northwest coast and central industrial belt.

Malaysia has long relied on foreign labor from Indonesia, which supplies the largest share of the country’s plantation and construction workforce. Better-paying jobs across the Strait of Malacca have drawn generations of Indonesian workers. But visa restrictions and the cost of legal migration push many toward unauthorized sea routes in overcrowded, often unseaworthy vessels. The pattern has produced recurring fatalities: boats overloaded, weather turning, coastlines near but unreachable.

The maritime office’s statement described the vessel only as a boat carrying undocumented migrants. It did not specify its size, condition, or whether it was intercepted before or after capsizing. The search area in the Strait of Malacca, one of the world’s busiest shipping corridors, is subject to strong currents and rapidly changing weather.