The tremors could be felt up to 180 km (110 miles) away in the Kenyan capital Nairobi where residential and high rise buildings shook gently for several minutes.

"There was a small one, then half an hour later there was a big one. The bed and the walls were shaking," a Reuters witness said of the early morning quake.

According to the USGS another magnitude 5.2 quake hit the region on Saturday.

Kenya and Tanzania lie along the geologically active Great Rift Valley.

The latest quakes revived July fears when panicked workers emptied high rise buildings after several tremors struck Nairobi over five days.

The government blamed the successive July quakes on stirring underneath Ol Donyo Lengai, an active volcano 240 km (150 miles) southwest of Nairobi in Tanzania.

Kenyan geologists could not immediately be reached to confirm the epicentre of the weekend quakes.

The last time a major quake struck the region was December 2005.