Police swiftly ended a problem when they stormed Manila airport's control tower this weekend, but the timing of the brief siege during a brewing constitutional crisis and rumours of military unrest meant the damage was already done.

From an optimistic point of view, the killing of two men who took over the control tower of the Philippines' main airport in the early hours of Saturday morning showed the government is willing and able to take a firm hand against threats to security. But even if the case was an isolated incident over grievances about corruption, as seems likely, it has raised the political temperature ahead of elections in May and worsened an image problem that is frightening away foreign investment.

High-profile security breaches are another warning sign for investors already declining to put money into an economy with about $25 billion in foreign debt, a chronic deficit and entrenched corruption in the bureaucracy and political system.

?It's another example of how things can go wrong so quickly here -- at an airport where one would expect there to be much tighter security?, said a foreign analyst, who asked not to be identified. ?It's quite alarming, I think.?

In the few hours before he and his companion were shot dead by police, former aviation chief Panfilo Villaruel embarrassed the government by showing up lax security and complaining about high-level graft.

The same complaints were made by soldiers who staged an aborted coup in July and the inevitable conspiracy theories that Villaruel was acting with military backing have started swirling.

The Philippine Daily Inquirer newspaper quoted unnamed military officials yesterday as saying Villaruel may have been waiting for an armed forces unit that failed to show up or was acting with the support of some politicians.

Stuart Grudgings