Beirut  - Hundreds of villagers in southern Lebanon prepared to sleep in the open on Tuesday amid rumours the region could be hit by a strong earthquake.

The panic was apparently triggered by a letter from Israeli authorities to health officials in the north of the country bordering Lebanon, advising them to make preparations for such an event.

But the secretary-general of the National Scientific Research Centre in Lebanon, Moeen Hamzeh, dismissed the idea.

"Chances of having an earthquake are impossible," he said in a statement published by the state-run National News Agency.

Since February, abnormal seismic activity has been noted in southern Lebanon, which had suffered some 500 minor earthquakes in a three-month period.

"The tremors increased significantly in May and June and this is what caused the worries and alerted us but no one can ever predict such earthquakes," Hamzeh added.

Lebanese radios quoted the Israeli Health Ministry as warning Monday of an increased likelihood of a powerful earthquake originating in Lebanon and being felt in its neighbour.

Some seismologists in Israel say that strong quakes have historically rocked the region every eight decades, and the last one was nearly 81 years ago.

About 300 people were killed in Jerusalem and nearby Jericho by the July 11, 1927 temblor.

A powerful quake in 1837 that hit the Houla Valley near the border with northern Israel devastated the town of Safed and killed some 4,000 people. (dpa)