BANGKOK (AP) — Rescuers retrieved a body floating in the sea after a boat carrying 30 people capsized off Thailand's southwestern coast, officials said. The search continued for six more people, including five foreigners, reported missing.

Authorities and fishermen plucked 23 divers from the sea a few hours after the boat sank early Monday and rushed them to local hospitals, said marine police officer Parinya Kaewplung. The boat was about 12 miles off the coastal Phang Nga province when it went down.

"We found a female Caucasian body near where the accident occurred," said Parinya. "But the body has not been identified." Parinya said rescuers were searching for six others.

Earlier, authorities said two Swiss nationals, two Austrians, a Japanese, a German and a Thai were missing.

All were tourists who were on a diving expedition except for the Thai national, who served as the boat's cook.

Authorities were investigating the cause of accident.

Boating accidents in Thailand are normally blamed on rough seas during the monsoon season or overcrowding and poorly enforced safety standards.

The seas were calm before the accident, Parinya said.

The boat was returning from the Similan islands, located 75 miles northwest of Phuket, an island that is one of Thailand's top tourist destinations.