Rice prices hit the $1,000-a-tonne level for the first time on Thursday as panicking importers scrambled to secure supplies, exacerbating the tightness already provoked by export restrictions in Vietnam, India, Egypt, China and Cambodia.

The jump came as the Philippines, the largest rice importer, failed for the fourth time to secure as much rice as it wanted.

The unsuccessful tender followed Bangladesh's inability to buy any rice at all this week.

Traders and analysts warned that rice demand was escalating in spite of prices rising to three times the level of a year ago as countries try to build up stocks.