Social media users have shared numerous photos and videos of the explosion site in the Tunisian capital, showing people running on the streets.
The attacker detonated an explosive belt targeting security forces on the way to the US Embassy, radio station Mosaique FM reported.
According to reports, at least five people have been injured in the blast, however, the number of victims may increase.
In the meantime, Tunisian law enforcement has started an investigation into the matter.
Last June, four people, including security forces, were injured in an explosion that targeted a police vehicle and took place on central Tunis' Habib Bourguiba Avenue near the French Embassy.