Aussies spark Changi alert

Fighter jets were scrambled and a massive security alert sparked when two Australians flew a light plane into Singapore's busy airspace without permission.

Commercial airspace over one of the world's busiest airports was locked down for 50 minutes early Wednesday, the Straits Times reported.

The two unnamed occupants of the Australian plane were questioned by Singapore's police but yesterday no charges had been laid.

The shutdown at Changi Airport forced at least 16 aircraft to circle, delaying arrivals and departures. One plane diverted to Malaysia as it ran low on fuel.

The Air Force sent F16s to intercept the Cessna 208 Caravan float plane after tracking its approach from Thailand and discovering it had no approved flight plan.

- AAP