The Star quoted Malaysian Maritime Enforcement Agency (MMEA) regional director Che Adnan Md Isa as saying that the boats were spotted illegally entering waters off the Tanjung Kubong coast at the northern tip of Labuan Island, at 11 a.m. on Saturday. The detained Vietnamese fishermen, aged between 19 and 57, had valid identification documents but the boats’ fish holds had been modified into diesel storage units, the agency said. The fishermen have been taken to a detention center in Labuan for further action. The seizure of the Vietnamese fishing boats is part of a large-scale crackdown by the Malaysian government on encroachment and/or illegal fishing activities by foreigners. Hundreds of Vietnamese fishermen have been charged with fishing violations in foreign waters in recent years. Indonesian authorities last week destroyed 125 foreign vessels, including 86 from Vietnam at 11 different locations in the country as part of greater efforts to prevent illegal poaching in its waters, The Star Online reported. Vietnamese authorities have been trying to raise awareness about maritime boundaries and international maritime laws among Vietnamese fishermen. They have also increased the frequency of patrols to try and prevent potential violations.