Jakarta – At least half of the famed Kuta Beach on the Indonesian resort island of Bali has been eroded by waves, an official said Monday.

"The damage has reached a critical level, covering 50 percent of the beach," said Tjok Bagus Budiana, head of the Bali Beach Restoration Project.

Budiana, quoted by the state Antara news agency, blamed the erosion of the 6.5-km beach on construction of the nearby Ngurah Rai airport, which he said changed the wave pattern. The damage was also due to the improper construction of seawalls and the destruction of coral reefs due to dynamite fishing.

The government would need the involvement of local administrations to formulate a long-term project to preserve the beach, he said. Some 15-20 percent of Bali's 430 kilometres of beaches has been damaged by erosion and illegal sand quarrying, Antara said.