Kenya sent hundreds of troops to Somalia in pursuit of al-Shabab fighters it blames for  kidnappings in Kenya [EPA]

Residents say a large number of Ethiopian troops have crossed into neighbouring Somalia, just weeks after Kenyan forces entered the country to pursue al-Shabab fighters.

"The Ethiopian troops, which are in convoys of armoured vehicles, come to us today, crossing from Balanbale district on the border," Gabobe Adan, an elder in the central town of Guriel told Reuters.

"They were in about 28 trucks and armed battle wagons - the armed vehicles are very big."

Other residents told Reuters that the Ethiopians had set up a base in Guriel and moved troops to other towns nearby.

Residents and officials in northeast Kenya later told Reuters that Ethiopian troops had also crossed through their towns and taken up positions near bases from where the Kenyan military is launching its offensive.

"We have seen Ethiopian troops. They are clearly known to us," a local named Lesamow Said told Reuters.

"They arrived this evening at Damasa. Some of the soldiers crossed over to the Somalia side and started patrolling immediately."

People in the Kenyan town of Mandera, which is near both Somalia and Ethiopia, said the Ethiopians had passed through there in a convoy of 10 trucks and several armoured vehicles.

'No confirmation'

A spokesman for the Ethiopian government, Shimeles Kemal, would neither confirm nor deny the reports.

Another Ethiopian official told Reuters that an Ethiopian move to support the Kenyan assault on the al Qaeda-linked al
Shabab group was likely.

"There is a strong possibility that we will be sending troops to Somalia soon to support Kenya's operation against the al Shabab extremists," the official said, speaking on condition of anonymity.

"Our deployment could either be implemented under the umbrella of AMISOM or under another form, such as a separate operation alongside Kenya," he said.

AMISOM is an African Union force of Ugandan and Burundian troops that has been largely responsible for keeping al Shabab from ousting the internationally backed government.

Kenya sent hundreds of the troops to Somalia in mid-October in pursuit of al-Shabab fighters it blames for a string of kidnappings in Kenya.