Tehran has voiced support for the uprising against the Libyan leader, part of what it considers an "Islamic awakening" in the Arab world.
But as a long-time foe of the United States which in recent years has invaded and stationed troops in two of its neighbours, Iraq and Afghanistan, Iran expressed deep suspicion over Western military intervention in Libya.
"The records and the actions of the dominant countries in occupying oppressed countries means their intentions in such moves are always in doubt," Foreign Ministry spokesman Ramin Mehmanparast was quoted as saying by students' news agency ISNA.
European and U.S. forces began bombing Libyan targets after a U.N. Security Council vote endorsed intervention aimed at protecting civilians at risk from Gaddafi's violent suppression.
While Iran's position "is always to support the people and defend their legitimate demands", Mehmanparast warned Libyans against an eventual occupation by the Western countries which are claiming to protect them.
"These countries enter usually with seductive slogans of supporting the people but they follow their own interests in ruling the countries and continuing colonialism in a new form," he said.
While voicing support for demonstrators in the Arab world, and condemning government repression, Iran has crushed protests at home and jailed scores of demonstrators since 2009.