印度尼西亚菲律宾就安全合作问题举行会谈

The Philippines and Indonesia are working together to stop supporters of the Islamic State terror group from entering the Philippines.

Indonesian Foreign Minister Retno Marsudi recently met with Philippine President Rodrigo Duterte in the southern city of Davao for talks.

The discussion centered on Islamic State sympathizers in Indonesia going to the Philippines to join anti-government fighters.

Duterte and the Indonesian foreign minister agreed to additional cooperation in stopping terrorism. The website of the president's office said they also discussed "maritime security."

Indonesia is mainly a Muslim country. It has so-called sleeper cells of people who sympathize with the Islamic State. The extremist group has mainly been driven out of bases in Iraq and Syria.

The U.S.-based SITE Intelligence Group says that in 2016 Islamic State, or IS, picked a Filipino rebel as its leader in Southeast Asia. Reports, however, say that he was recently killed.

Some Indonesian sympathizers worked with Filipino rebels in a five-month war in the southern Philippines last year.

Philippine officials believe that Indonesians and also Malaysians went to the southern island Mindanao at that time. They are believed to have supported local rebels who sympathize with the Islamic State group. That fighting in the Philippines killed at least 1,127 people, including more than 900 militants.

In October, Philippine troops declared victory over the Maute Group of Muslim rebels. The group had declared allegiance to Islamic State, which is also referred to as ISIS.

A police spokesman in Jakarta told reporters that at least 38 Indonesians were helping Philippine rebels as of last June. That is one month after fighting broke out in the Philippine city of Marawi.

Bibhu Routray is a visiting security and counter-terrorism professor at Murdoch University in Australia. He says some of the 40 to 50 foreign rebel supporters in Marawi had traveled from Indonesia to fight for Islamic State after the group called for volunteers.

Thirty Indonesians got there from Syria and it is believed they were sent by Islamic State, Routray said. He added that on their return home they went through the Philippines. He said this suggests that Islamic State sent them to fight in Marawi.

The Indonesian government said in November it would support the Philippine efforts to stop Islamic State in Marawi. In June, the same government had sent 119 police officers and 200 special forces to Sulawesi Island to help the army stop terrorists.

Philippine officials have warned against new Muslim rebel violence in Mindanao although they say Marawi is under control.

Eduardo Araral is an associate professor at the National University of Singapore. He said, "I think it's logical that Indonesia should always keep its guards up, because they know for a fact that their main sleeper cells around Indonesia are waiting for opportunities to come."

About 20 Muslim rebel groups operate in Mindanao. The large island is rich in resources by economically poor.

People there say the majority Catholic country has taken a lopsided share of resources although there are many Muslims on the island.

Violence has killed about 120,000 people on Mindanao since the 1960s.

The Straits Times of Singapore online newspaper reports that Islamic State "sleeper cells" operate in most Indonesian provinces.

The extremist Islamic group East Indonesia Mujaheedin recruits young people on Sulawesi Island. It has promised to support Islamic State.

Experts say there is a lack of security patrols in the Celebes Sea. The body of water south of Mindanao and east of Borneo.

But Indonesia and the Philippines do have reached maritime agreements before.

They signed an agreement in 2014 after twenty years of talks on formal boundaries around their economic zones in the Celebes Sea.

I'm Susan Shand

Ralph Jennings reported this story for VOA News. Susan Shand adapted it for VOA Learning English. Mario Ritter was the editor.