Madrid  - The rising level of the river Ebro, sparked by heavy rains in May, is worrying the organizers of the 2008 World Expo in the northern Spanish city of Zaragoza, press reports said Tuesday.

The organizers were taking emergency measures to protect the Expo installations on the river bank.

Spain's most abundant river was flowing at 1,337 cubic metres per second in Zaragoza on Tuesday, an unusually high level for the month of June.

The overflowing of the Ebro left thousands of hectares of farmland under water in Zaragoza province.

If the river flow exceeds 700 cubic metres on the inauguration day of the Expo on June 13, organizers intend to cancel a spectacle involving an iceberg which appears on the river, and to replace it with an alternative programme.

A general rehearsal, with tens of thousands of local people as the public, has also been suspended, reports said. Dykes have been erected and other measures taken to protect the Expo installations on the river bank.

It is as if the Ebro wanted to make its presence clear at the Expo, which will be dedicated to the theme of water and sustainable development, the daily El Mundo quipped. (dpa)