KUALA LUMPUR -- Three Southeast Asian countries on Thursday launched trilateral air patrols and intelligence sharing, aiming to keep a lid on Islamist militancy in the region.
The move follows joint sea patrols that began in June in the Sulu Sea off the southern Philippine island of Mindanao.
The latest initiative is part of a three-way agreement reached a year ago aimed at tackling threats from terrorist organizations, including pro-Islamic State militants who operate in the area.
"Our three nations have recognized the importance and gravity of the situation in the Sulu Sea," said Hishammuddin Hussein, Malaysia's defense minister.
He said a proactive approach to safeguard the region is necessary, considering the strategic location of the waters for global trade. The three countries' "greatest fear" in confronting foreign fighters is IS returning to the region, Hishammuddin said.
Joint patrols are not new to the region. In previous years, countries worked together in the Strait of Malacca to fight piracy and cross-border pollution caused by forest clearing. Anti-piracy cooperation between Malaysia, Thailand, Singapore and Indonesia led the Lloyds Joint War Committee, which represents marine underwriters, to remove the waters around the strait from its list of "war-risk zones."
Malaysia said $40 billion worth of goods pass through the Sulu Sea waters annually, highlighting the importance of securing shipping lanes for cross-border trade, in addition to fisheries.
Led by the Malaysian air force, joint air patrols will begin in November. Aircrews from all three countries will take turns conducting reconnaissance missions.
Due to the wide area where the maritime borders converge, the three countries also agreed to coordinate patrols by their air forces and to share intelligence.
The ministers said the joint patrols will only involve members of the Association of Southeast Asian Nations, although Australia, China and the U.S. have expressed interest in providing support.
"We have to stand firm, to show that we are capable to solve our problems within ASEAN," said Ryamizard Ryacudu, Indonesia's defense minister.
In June, the three neighbors established a joint control center in Tarakan, a port city in northeastern Borneo, Indonesia. The show of force is a sign of their determination to combat cross-border terrorism. It follows an attempt by the pro-IS Maute group to seize Marawi in Mindanao. That action drew retaliation by the Philippine armed forces and resulted in massive casualties.
Resort islands in the Malaysian part of Borneo have also been targeted frequently in recent years by kidnappers allegedly linked to terrorist groups from the southern Philippines. Deadly abductions of tourists and resort employees were so rampant at one stage that Malaysia was forced to declare a state of emergency in eastern Sabah and set up a military outpost.
Researcher Ying Xian Wong contributed to this report.