JAKARTA, Aug 2 — A powerful earthquake that struck off the southern coast of Indonesia’s heavily populated Java island could spark a tsunami as high as three metres, the disaster agency warned today.

"There are some areas at risk of a serious threat of a tsunami that could be as high as three metres,” said agency official Rahmat Triyono.

"We’re still waiting for reports about damage” from the quake, he added.

The United States Geological Survey earlier put the magnitude of the quake at 6.8, before raising it to 6.9. — AFP