Jakarta (AsiaNews/Agencies) - Fifty people were killed and about 300 homes destroyed on the island of Nias, near the epicentre of a massive earthquake that struck off the coast of Indonesia on Monday, a government official said. The powerful earthquake is spreading panic but there have been no reports yet of it triggering any tsunamis, UN emergency relief office said on Monday. Meanwhile evacuation orders issued in Thailand and Sri Lanka were cancelled.

Up to now the Nias Island seems to be the worst hit. Agus Mendrofa, the deputy mayor of Gunungsitoli town, estimated that 10,000 people had fled for higher ground. "I can guarantee that dozens have died," Mr Mendrofa said by telephone.  "Gunungsitoli is now like a ghost town. The situation here is one of great fear". Mr Mendrofa added that roads had also been cracked by the quake.

Meanwhile, a tidal gauge has detected a small tsunami in the Indian Ocean several hundred miles south-west of the earthquake.

The US Geological Survey reported that an instrument near the Cocos Islands recorded the passing wave, but the magnitude of the "small" tsunami was not clear, perhaps between one and two metres high. The waves are not considered destructive but people have been urged to use caution on or near the water.

The agency said no major tsunami has been observed near the quake's epicentre which was upgraded from a magnitude of 8.2 to 8.7. An aftershock measuring 6.0 struck 30 minutes after the initial quake.

UN emergency relief coordinator Jan Egeland said there have been no reports yet of any tsunamis. Therefore, evacuation orders issued in Thailand and Sri Lanka were cancelled.

The quake that struck on Monday was of a magnitude of 8.7. While still "very large," it was smaller than the one that hit the region on December 26, devastating coastal areas and triggering giant waves that left nearly 300,000 people dead or missing across southern Asia and as far away as Somalia on Africa's east coast.

Indonesia's Metro TV reported that power failure hit Banda Aceh, the capital of Aceh Province after the quake.  In Singapore the quake caused tremors in many parts of the country.

The UN said monitoring centres were able to alert governments bordering the Indian Ocean, which were in turn able to get word of the quake to local officials.

The affected areas were in any case better prepared for disaster this time around, Mr Egeland said.