The fishermen were arrested by the officers of the Maritime Resource Surveillance Agency from three vessels poaching in Indonesia's Exclusive Economic Zone of North Natuna waters.
"The three fishing vessels operated in Indonesian waters without any legal documents and were using trawl nets which are banned in the country," he said.
The three vessels are KG 95118 with two crew members detained by a Macan 01 patrol ship, KG 94629 TS with 10 crew detained by an Orca 03 patrol ship, and KG 93255 TS with 15 crew arrested by a Hiu 11 patrol ship.
"The 27 foreign fishermen were handed over to the Pontianak Immigration Office for further investigation over alleged violation of immigration rules," he added.
The fishermen claimed they had not realized they had entered Indonesian territory and they were only tasked to pull up the trawl net.
"Based on our preliminary investigations, the fishermen have violated the regulation for using the banned trawl that could endanger Indonesia's sea resources," Suheryadin said.
The fishermen would be charged under Article 75 of Law no 6/2011 on immigration, and the boat skippers would also be charged under Law No. 45/2009 on fisheries.
Last week, the Directorate General of Marine Resources Surveillance of the Maritime Affairs and Fisheries Ministry detained five foreign boats fishing illegally in North Natuna Sea in Riau Islands and arrested 68 Vietnamese crew members.
The vessels were first detected by the ministry's surveillance ship in Indonesia's Exclusive Economic Zone, southwest of Tarempa Island bordering the overlapping claimed area between Indonesia and Malaysia.
The boats attempted to capitalize on the agreement between Indonesia and Malaysia to expel ships operating in the overlapping claim area.
Related news: Seized Chinese fishing vessel sank in Semau Island waters, NTT
Related news: Fisheries Ministry detains five foreign fishing boats in Natuna