A North Carolina man has been convicted in the District of punching a foreign ambassador and knocking him down, authorities said.

Leon Obame, 44, of Raleigh, was found guilty Thursday of assault on a foreign official in connection with an attack on the ambassador of Gabon, said the U.S. Attorney’s office for the District of Columbia.

The attack occurred Dec. 9, 2011, during a demonstration at Gabon’s embassy, then in temporary quarters in the 1600 block of Connecticut Avenue, the prosecutors’ office said.

Attacks on foreign diplomats here are extremely rare, and U.S. Attorney Ronald C. Machen Jr., called them serious crimes that are not to be tolerated.

“Those who engage in these kinds of attacks will be held fully accountable,” he said in a statement.

A posting on the Web site of the Gabonese-American Council on Human Rights and Good Governance said Obame was a “long-time foe of the powerful Bongo family” that has ruled the nation since 1967. Gabon is in western Central Africa.

Obame had also been charged with arson and with damage to property occupied by a foreign government in connection with two 2009 fires at the embassy, which is on 20th Street NW. The jury failed to reach a verdict on those charges, prosecutors said.

Obame, who pleaded not guilty to all the charges, has been in custody since his arrest, the prosecutor said.

They said the assault charge carries a maximum penalty of three years.