Four South East Asian nations have launched joint air patrols of the Malacca Strait, in a bid to deter pirate attacks.
The four countries will take it in turns to monitor the strait
Planes from Malaysia, Singapore, Indonesia and Thailand will be allowed to cross into each other's air space under the scheme.
The four countries will initially take turns conducting two patrols a week.
The strait is one of the world's busiest sea lanes, carrying half its oil and a quarter of its commerce.
But it is also becoming increasingly notorious for pirates, and 27pirate attacks were reported in the waterway last year.
The first aircraft to take part in the Eyes in the Sky project, a Malaysian C130 Hercules, took off from Kuala Lumpur's Subang Airport with a crew from Indonesia, Malaysia and Singapore on Tuesday.
"Hopefully this will send a very strong message to the international community that we are serious about maintaining the security of the Malacca Strait," said Malaysian Defence Minister Najib Razak.
He added that he hoped other countries, including the US and Australia, would offer to participate in the scheme.
Indonesia and Malaysia rejected the US's offer last year that American forces help patrol the strait.
From the point where the Malacca Straits are at their narrowest, the Indonesian island of Batam can clearly be seen on one side and the skyscrapers of Singapore on the other.
Piracy has been a problem on the waterway for centuries, but it has been getting worse in recent years. Since the 11 September attacks on the US, the threat of attacks in the region has also increased.
Last year, Indonesia, Malaysia and Singapore launched joint naval patrols of the strait.