French police said a "small explosion" occurred at the Tunisian consulate in a Paris suburb early Sunday, which the country's ambassador denounced as a "terrorist act".

The blast took place around 5:00 am (0400 GMT) at Tunisia's office in Pantin and "caused minor damage to the consulate's metal shutters," said police, who have opened an investigation.

It could have been a petrol bomb that caused the explosion, local officials said.

Tunisia's ambassador to France, Raouf Najar, said in a statement sent to AFP: "The disinformation these past few days on what is happening in Tunisia is such that anything is possible, even this terrorist act."

In Tunisia protests sparked by high youth unemployment and the rising cost of living have erupted across the north African country. At least nine people have died in the unrest, some from gunshot wounds and others committing suicide.

Authoritarian President Zine El Abidine Ben Ali has fired three ministers and a regional governor, and accused the opposition of exaggerating the scale of the protests.

The consulate in Pantin opened for business later Sunday morning with a police guard outside.