TOKYO (Reuters) - Japan will build four coast guard radar stations on islands in the Sulu Celebes Seas separating the Philippines and Indonesia to help Manila counter a surge in piracy by Islamic insurgents, two sources said.

An agreement to fund the facilities and provide training to local coast guard personnel may be signed as early next week by Japanese Prime Minister and Philippine President Rodrigo Duterte in Manila, the sources said.

“The seas in that area are an important waterway for merchant ships traveling to Japanese ports,” one of the people with knowledge of the plan said. The sources asked not to be identified because they are not authorized to talk to the media.

Of 30 acts of piracy reported in the first half of 2017 six involved the use of guns, of which three were crew abductions from ships underway in the Sulu Celebes Seas, according to the Regional Cooperation Agreement on Combating Piracy and Armed Robbery against Ships in Asia (ReCAAP). Four attempted abductions in the waters were also logged.

Japan will fund construction of the radar stations through its Overseas Development Aid (ODA) budget, the sources said.

“Japan is aware of the need to counter piracy in the region and is keen to help, but we can’t discuss individual projects,” said an official at Japan’s Ministry of Foreign Affairs, which overseas ODA spending.

The radar stations are part of a wider aid package that include helicopter parts for the Philippines military, financing for infrastructure projects such as rail lines and help to rebuild conflict-torn southern Marawi city after five months of military operations against Islamic State rebels.

By providing such aid Tokyo is aiming to deepen economic and security ties with Manila as it looks to contain China’s growing power. Japan sees the Philippines, which lies on the eastern side of the South China Sea, as a key ally in helping prevent Beijing’s influence spreading into the western Pacific.

Abe will travel to the Philippines on Monday following a two day gathering of regional leaders at an Asia Pacific Economic Cooperation (APEC) forum in Vietnam.