Earthquakes measuring up to 5.5 on the Richter scale have been rattling northeastern Tanzania in the past four days and tremors were also felt in neighbouring Kenya, officials said Sunday.

Kenya Meteorological Department official Peter Ambenje said the tremors, which lasted about one minute, were last recorded in northeastern Tanzania at around 2:24 pm (1124 GMT) on Sunday.

"More earthquakes will be felt in the area because it lies on East Africa's Great Rift Valley which runs along a geological fault line," he said.

"Kenyans should not be worried because we are unlikely to be affected by the tremors," he added after Nairobi residents reported feeling quakes.

There were no immediate reports of damage.

In December 2005, a powerful earthquake struck the Lake Tanganyika region of East Africa.

That quake, which French geologists said registered 7.5 on the Richter scale and US geologists said was a magnitude 6.8, shook buildings in cities throughout the east and central African region.