No damage or injuries were immediately reported from the temblor that registered 7.5 on the Richter scale, according to the French Observatory of Earth Sciences in Strasbourg and magnitude 6.8, according to the US Geological Survey (USGS).

The two facilities said the epicenter was near the eastern side of Lake Tanganyika, the largest of the chain of bodies of water in the Rift Valley which forms the border between Tanzania and the DRC.

"A strong earthquake occurred at 12:19:55 GMT (3:19 pm local time in most of the affected countries) in the Lake Tanganyika region," the USGS said on its website.

The exact coordinates were 6.9 degrees on the southern latitude and 30.8 degrees longitude east, near the Tanzanian village of Sibwesa, the French organinzation said.

In the Ethiopian capital, where the quake was not felt, the seismology department at the University of Addis Ababa said the quake occurred 20 kilometers (12.5 miles) underground and was the most powerful to hit the Rift Valley in a decade.

"This is the highest magnitude ever recorded in the region for about a decade," said Atalay Ayle, the head of university's geophysics lab.

"The effects can be felt from the epicenter across the region," he told AFP.

Residents of towns and cities in at least six countries in the region -- Burundi, the DRC, Kenya, Rwanda, Tanzania and Uganda -- reported feeling the tremors.

In the Kenyan capital, some 900 kilometers (560 miles) away from the epicenter, and the port city of Mombasa, tall buildings swayed as the earth shook for some 15 seconds sending thousands of office workers fleeing.

"I was sitting at my desk when I started feeling dizzy," said an AFP journalist who was in the news agency's office on the fifth floor of a 13-story building in downtown Nairobi. "Everything was swaying."

"The tremor lasted about 15 seconds, then we decided to leave the building," he said.

Kenya's private Nation television reported that cracks had been seen in some downtown buildings after the temblor but this could not immediately be confirmed.

In the northern Tanzania, residents also felt the quake which forced the evacuation of the International Criminal Tribunal for Rwanda (ICTR) which is trying suspects in that country's 1994 genocide, witnesses said.

In Rwanda itself, residents of the capital Kigali said they had felt the earth shaking as did witnesses in the Ugandan capital of Kampala, the Burundian capital of Bujumbura and several towns in the eastern DRC.

In Bujumbura, the outskirts of which border Lake Tanganyika, an AFP correspondent reported that the lake's waters appeared "more rough than normal" but said residents of the area had reported no damage.

As in Nairobi, Kampala and Arusha, large office buildings in Bujumbura were evacuated, the correspondent said.

A geologist at the University of Nairobi said the quake was not entirely unexpected in the Rift Valley, the 5,000-kilometer (3,125-mile) long chasm that runs from northern Syria through Africa to Mozambique.

"We had similar tremors in western Kenya and Rift Valley province about three years ago," the geologist said without commenting on the magnitude of Monday's quake.

"Recent studies have indicated that some parts (of the) Rift Valley and Indian Ocean will be frequented by mudslides, tremors and eruptions," he told

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.