TUNIS (Reuters) - Four Tunisian police officers and one armed Islamist were killed in clashes in the northwest and center of the country, including one where gunmen tried to take civilians hostage before being shot, authorities said on Monday.
The attacks came as Tunisian security forces try to crack down on armed Islamist militants following the attack on the Bardo museum in Tunis in March when gunmen killed a group of foreign tourists there.
Tunisia is hailed as a model for transition following its 2011 uprising against autocrat Zine El-Abidine Ben Ali, but the threat from hardline Islamist groups has become one of the fledgling democracy's toughest challenges.
Gunmen attacked a checkpoint in Sidi Bouzid, killing two policemen and then shooting a third in another clash, state news agency TAP reported. One gunman was killed and another seriously wounded.
Interior Ministry secretary of state Rafik Chelli said the gunmen "had tried to take eight civilians hostage and opened fire on a military helicopter with Kalashnikovs before we killed one and arrested the other."
In a separate attack later on Monday, another policeman was killed and four wounded in clashes with gunmen in Jendouba, a northwestern region close to Algeria's border, interior ministry spokesman Mohamed Ali Aroui said.
No group claimed Monday's attacks, but several small brigades of Islamist armed groups are active in Tunisia, including Okba Ibn Nafaa, which operates along the border with Algeria. One of its Algerian commanders was blamed by Tunisian officials for orchestrating the Bardo assault.
Reporting by Tarek Amara; writing by Patrick Markey; Editing by Dominic Evans