A bomb planted underneath a police car exploded on July 27 in the Tunisian capital, Tunis, just hours before a slain opposition figure was due to be buried.
Tunis police say the blast, set off by remote control, shattered windows and damaged nearby cars but caused no injuries.
The explosion comes a day after the Tunisian government announced that an Al-Qaeda cell was responsible for the July 25 assassination of a secular opposition politician, Muhammad Brahmi.
The Interior Ministry said the alleged assassin, Boubacar Hakim, was also suspected in the killing of a second opposition figure in February and that the same gun was used in each attack.
Brahmi is being buried under military guard.
Many Tunisians have blamed the moderate Islamist government for the country's lack of security since the country's pro-democracy uprising in 2011.
Based on reporting by AFP and AP