An Ethiopian rebel group says it has killed more than 250 soldiers this week during fighting with government forces.

There has been no outside confirmation of the claim by the rebel Ogaden National Liberation Front, which says it attacked soldiers near the southeastern town of Wardheer on Saturday.

Speaking to parliament Tuesday, Ethiopian Prime Minister Meles Zenawi did not refute reports of heavy losses, but made light of the ONLF's claim that it had encircled government troops and forced presidential aide Abay Tsehaye to flee by helicopter.

That claim was made in the ONLF's initial statement on the fighting, issued Sunday, in which the group claimed a government death toll of 140. 

The latest ONLF statement, issued late Monday, said government forces counter-attacked the rebels on Sunday but were beaten back. 

The ONLF said its fighters surrounded a large number of government troops near Wardheer and were urging them to surrender.

The ONLF is an ethnic Somali movement that has waged a mostly low-level insurgency in eastern Ethiopia for more than 20 years.  The government launched a new crackdown against the group after it attacked an oil exploration field in April, killing 74 people.

The rebels said their latest attack was a response to alleged government abuses against the people of the Ogaden region and the burning of Caado village near Wadheer.