Prime Minister Meles Zenawi's government spied on citizens and especially persecuted those seen as supporting the Oromo Liberation Front (OLF), said the report, dated Feb. 28.

The rebel group is fighting Addis Ababa over what its perceives as the marginalisation of the Oromo people.

"Although there were improvements on the government's human rights record, serious problems still remain -- security forces committed a number of unlawful killings, including alleged political killings, beatings and torture," the report said.

"The government continued to arrest and detain persons arbitrarily, particularly those suspected of sympathising with or being a member of the OLF."

Other violations included illegal property searches, harassment of opposition political parties and journalists and monitoring of phone calls and email, the report said.

The Ethiopian Foreign Ministry called the report "baseless and frivolous".

"It could not in any way be taken as serious, as it was essentially based on rumours, lies and innuendoes peddled by foreign-financed groups", the ministry said in a statement.

It did not identify the groups it believed were responsible.

"The objective of the sources of lies and the innuendoes has always been obviously tainting the image of the country and making sure that Ethiopia's credibility will not be enhanced," the ministry added.

The United States and Ethiopia generally enjoy good relations, particularly since Ethiopia's nominally Christian government is seen as a stalwart against Islamist influence in the Horn of Africa.

It is also seen a key partner for U.S. anti-terrorism activities in the region.

Source: Reuters