At least 34 people are dead after a sudden thunderstorm caused a tourist boat to capsize in Vietnam on Saturday, according to local reports. 

The vessel, named Wonder Seas, was carrying 48 passengers and five crew members during a sightseeing excursion of Ha Long Bay, a popular destination for visitors, according to reports cited by The Associated Press. 

Rescue workers saved 11 people and recovered the dead near the site of the capsizing, VNExpress newspaper said. Search teams are frantically looking for the missing victims of the disaster. 

Survivors of the capsized boat in Vietnam were rescued on Saturday. (Associated Press)

A group of 15 divers went into the sea to search for victims and survivors. 

An eyewitness told AFP news agency that the sky darkened around 2 p.m. local time on Saturday.

There were “hailstones as big as toes with torrential rain, thunderstorm and lightning”, he said, per the BBC.

It does not appear that any Americans were on board. Fox News Digital has reached out to the State Department for clarification,

Tourist boats travel in Ha Long Bay in Vietnam on Oct. 24, 2015. (AP Photo/Huy Han)

Ha Long Bay is located in Quang Ninh Province in northern Vietnam and is one of the country’s most iconic natural landmarks, featuring more than 1,600 limestone islands and islets. “Ha Long,” means “Descending Dragon,” and local folklore says the islands were formed by a dragon’s tail crashing into the sea.

The Associated Press contributed to this report.