TEGUCIGALPA, Honduras (AP) _ A powerful bomb Wednesday destroyed a human rights activist's parked car and damaged two buildings in the southern suburb of Miraflores.

No injuries were reported in the blast, heard throughout most of Tegucigalpa. A police source, who asked not to be identified for security reasons, said two suspects were arrested.

Neighbors said the bomb went off at 5:10 a.m. under the car parked outside the home of Leonor Meza, 38, who teaches sociology at the National University and is a leader of the 15,000-member Unitary Federation of Honduras, a leftist labor union.

No person or group immediately claimed responsibility for the attack, but Ms. Meza blamed Nicaraguan rebels based in Honduras.

The rebels, known as Contras, are fighting to overthrow the leftist Sandinista government in neighboring Nicaragua.

''The counterrevolutionaries who operate in the country with the tacit approval of the authorities and the help of anti-patriotic groups are responsible for this,'' Ms. Meza told reporters.

The explosion was the latest in a rash of bomb attacks around Tegucigalpa in the past three months. An incendiary bomb was hurled at Ms. Meza's home in October, but it caused little damage.

A powerful bomb exploded Dec. 26 in the building housing La Prensa, the country's principal newspaper, destroying the entire second floor. Bombs also were found later at the Israeli and Mexican embassies and were defused by police.