Their boat, disguised as a Malaysian boat, was discovered Tuesday 41 nautical miles off the coast of Miri, Mohd Fauzi Othman, chief of the Malaysian Maritime Enforcement Agency in Miri, said.

Six tons of fish worth about RM500,000 ($119,000) on the boat were also seized.

The Vietnamese, aged between 16 and 46, had no permit to fish in Malaysian waters, Othman said.

The boat and crew were taken to Miri Wednesday morning, and would be charged for illegal fishing, he added.

Vietnamese fishermen are increasingly being caught in neighboring countries’ waters.

Malaysian authorities detained 25 Vietnamese vessels and 123 crew members in a major crackdown from May 2 to 16.

They arrested 33 fishermen last week for trespassing into Malaysian waters and carrying out electric pulse fishing off the Sabah coast.

Despite its 3,260 km (2,025 miles) coastline, Vietnam is running out of near-shore seafood resources, and some fishermen who have sailed into other countries’ waters also said they face threats from Chinese trawlers that are illegally anchored in Vietnamese waters.