BUJUMBURA, April 26 (Reuters) - Burundi’s president has called for regional and international action against the central African country’s last active rebel group, whose latest offensive killed 33 people in a week.

Fighters from the Forces for National Liberation (FNL) fired mortar bombs into the capital Bujumbura on Tuesday night, hitting the residence of the pope’s envoy, who was out of the country at the time. The attack did not seem targeted.

“Since April 17, the FNL has been throwing hand grenades and bombs, organising attacks here and there in the country, targeting especially the capital Bujumbura,” President Pierre Nkurunziza said in a speech to the nation late on Friday.

Despite a 2006 peace deal, FNL fighters have mounted sporadic attacks since talks to implement the accord were suspended last July when the rebels quit a truce monitoring team accusing mediators of bias.

“We call upon the international community, and in particular regional leaders, to work together and establish who between the government and the FNL has broken the ceasefire deal, and then take appropriate measures”, said Nkurunziza.

He did not specify the kind of measures to be taken.  Nkurunziza also strongly condemned the damage inflicted on the residence of Vatican representative Paul Richard Gallagher.

The FNL’ s persistent insurgency is regarded by many as the final barrier to lasting stability in the coffee growing nation of 8 million which is emerging from more than a decade of ethnic war that killed 300,000 people.

The FNL blames the government for the latest violence in the country.

“The government has chosen to chase and eliminate all FNL fighters and members, instead of granting them amnesty,” said FNL leader Agathon Rwasa from Dar es Salaam.

“Nkurunziza can seek support from U.N. or regional countries, but he must understand that would not bring lasting peace in Burundi,” Rwasa added.