Louise Berwick, who turns 17 next week, went to Tunisia in' />

A Timaru teenager on an AFS exchange has been caught up in Tunisia's violent uprising.

Louise Berwick, who turns 17 next week, went to Tunisia in August and is living with a family on the outskirts of the capital, Tunis, where long-term President Zine El Abidine Ben Ali was ousted on Friday, the Timaru Herald reported.

At least 78 people had been killed since the start of the uprising and the unrest had cost 3 billion dinars ($2.69 billion) in damages and lost business, a Tunisia Government spokesperson said.

Louise's mother, Imogen Berwick, said her daughter had heard gunshots outside her host family's home where she has been holed up since the unrest started.

While her daughter's situation was stressful, she preferred she stayed with her host family rather than trying to get to an airport, Mrs Berwick said.

Louise was also keen to stay, despite the unrest, she said.

Tunisia today (NZ time) unveiled a transitional unity government in which the toppled president's party holds on to key posts, and announced unprecedented freedoms and the release of all political prisoners.