TEHRAN -- Senior Iranian officials have confirmed that military actions staged by the rebel Iranian Liberation Army, made up largely of Army dissidents, are causing problems for Iranian forces in the war against Iraq.

"Hit-and-run strikes by uniformed counterrevolutionaries have resulted in the deaths of dozens of revolutionary guards in western Iran," said a senior Iranian official.

Mujahaddin-e-Khalq leader Massoud Rajavi announced the formation of the rebel army last June, with strong backing from Iraq. Baghdad reportedly has provided training facilities and staging grounds for the unit's operations, as well as headquarters facilities in the Iraqi capital.

Despite numerous claims of successful raids, however, it has been unclear what impact the unit has had on the Iranian government of Ayatollah Ruhollah Khomeini. The size of the rebel army and state of its training remain unclear. In recent weeks, however, the Persian-language press has started low-key coverage of operations of what they call the "liars."

The newspapers Etillat and Jahmdori Islam published photos three times in the last month of revolutionary guards who have been killed in clashes with dissident forces.

Activities of the dissident forces also have led to intensified security in Tehran and other cities, according to well-informed observers. Although Mujahaddin leaders say their group is not involved in terrorist incidents reported in various Iranian cities, authorities invariably blame them for bombings and other incidents.

In Tehran, all government offices are heavily guarded and people entering are subjected to search. The checks also extend to the tens of thousands of people who come for Friday prayers at Tehran University.

While Iranian authorities generally blame Iraq and other Arab states for the activities of the dissident forces, Pakistan also has come in for criticism recently.