Bangladesh on Sunday deployed armed border guards to an island near its southern border with Myanmar for the first time in 20 years, according to officials.

Border Guard Bangladesh (BGB) distributed images showing dozens of troops carrying assault rifles disembarking at Saint Martin’s island, a small island in the Bay of Bengal that has caused diplomatic tensions between the neighbors.

The BGB said the troop deployment was part of “regular activities” to protect the border and tackle drug trafficking.

But the force’s lieutenant colonel, Sarker Mohammad Mustafizur Rahman, told AFP it was the first time since 1997 that their guards had been deployed there.

“After more than 20 years we felt we should deploy,” he said.

The deployment comes just two months after Bangladesh’s Foreign Ministry summoned Myanmar’s ambassador in Dhaka to protest the inclusion of Saint Martin inside their territory in some maps printed inside the Southeast Asian country.

He was also summoned in October last year, after a Myanmar government website depicted the island as within Myanmar’s territory.

Ties between the neighbors have soured since the Myanmar military launched a crackdown on the Rohingya minority in Rakhine, a troubled western state bordering Bangladesh.