The Royal Solomon Islands Police Force is working with Bougainville police to step up border protection.

Police in Solomon Islands and Bougainville have pledged to work together to stop guns being carried across the border.

Years of conflict in both countries has led to a ready supply of small arms. And police say they have received reports of people moving across the border freely when carrying weapons.

Solomon Islands Assistant Police Commissioner Edward Sikua told Pacific Beat both countries were looking to develop strategies to monitor the movement of arms across the border.

"Certainly because of the conflicts on both sides of the border, the issue of arms moving across this border is an issue for both police forces," he said.

Assistant Commissioner Sikua was in Bougainville earlier this year to hold meetings with his Bougainville counterpart.

He said the movement of guns was not the only issue troubling police.

"There's lots of criminal activity happening along the border and it's in the interests of both forces to work together to address these activities," he said.

"It is a big concern for us, for all police forces - there are plenty of criminal activities."