Four Southeast Asian nations yesterday launched joint military air patrols over the Straits of Malacca and Singapore as part of measures to prevent piracy and terrorism in the busy waterway.

Indonesia, Malaysia, Singapore and Thailand said in a joint statement that other countries with a stake in the security of the straits are also welcome to join the Eyes in the Sky (EiS) project after a period of review.

The EiS project was proposed by Malaysia in June and launched operationally yesterday, with a C130 transporter of the Royal Malaysian Air Force flown by a crew from Indonesia, Malaysia and Singapore.

Initially each of the four countries will take turns conducting up to two patrols per week.

"Being a strategic channel and vital to international trade, security of the straits is of paramount importance to the littoral states, user states and other stakeholders," the four nations said in the statement.

They said the three nations which border the strait, together with Thailand, had agreed to conduct the combined air patrols "while respecting the sovereignty and the territorial integrity of the littoral states.

"Other friendly states and stakeholders would be welcomed in the near future after a period of review with the agreement of the littoral states," they said.

Malaysian Defence Minister Najib Razak said at a press conference that countries including the United States and Australia were welcome to participate as long as they meet the basic criteria to be set by the four founding nations.

"We hope that this is just the beginning. I consider this as phase one. Phase two will entail the involvement of the international community. We're hoping there will be offers from the international community to participate," he said.

"Hopefully this will send a very strong message to the international community that we are serious about maintaining the security of the Malacca Straits."

Maritime patrol aircraft

An EiS Operations Centre will be established in each of the four nations to coordinate flights, along with a Monitoring and Action Agency (MAA) in each country which will coordinate any responses within their own waters.

"Intervention will be done by the country who has sovereignty in that particular area," Najib said, emphasising the need to protect national sovereignty.

The armed forces of the participating states will each provide maritime patrol aircraft, operated by a Combined Maritime Patrol Team which which broadcast any suspicious activity to the MAA.

The Malacca Straits is one of the world's most important waterways, with 50,000 ships carrying about one-third of the globe's trade passing through it each year.

However the strait, 960 kilometres (600 miles) long and 1.2 kilometres wide at its narrowest point, is notoriously vulnerable to pirate attacks and governments in the region also believe it is a tempting target for terrorists.