Peacekeeping operations in East Timor have been disrupted because Royal Australian Air Force cargo planes have been affected by contaminated fuel.

One plane has been grounded after using the fuel which can cause engine blockages.

The contaminated fuel has already crippled light aircraft flights in Australia, and now the authorities in Papua New Guinea have quarantined stocks while they are checked.

The supplier of the fuel Exxon Mobil, says the problem was caused by increased use of a refining chemical. Australian aviation authorities say about five thousand light aircraft have been grounded.

Correspondents say transport, business, medical, agricultural and other services have been badly affected.

Organisations representing the aviation industry say the problem is costing their members millions of dollars and have warned of huge compensation claims.

From the newsroom of the BBC World Service