TUNIS (Reuters) -- Tunisian authorities said on Thursday they had arrested a "terrorist" group and seized a big arms cache, as security forces went on alert after a mass hostage-taking by Islamist militants in neighboring Algeria.
The arms included Kalashnikov rifles and rocket-propelled grenades, a security source said. A statement by the Ministry of Interior said they were discovered in the southern town of Medenin, without giving further details.
Al-Qaida-linked Islamists seized dozens of hostages in a raid on a gas field plant in southeast Algeria this week, to the south of Tunisia.
Twenty-five hostages escaped and six were killed on Thursday when Algerian forces launched an operation to free them, Algerian sources said.
The Islamists said that the attacks were in retaliation for Algeria allowing France to use its air space to carry out bombing raids in Mali.
Since the overthrow of former President Zine El Abidine Ben Ali two years ago, the influence of radical Islamists in Tunisia has increased. Secularist groups have accused the ruling moderate Islamist Ennahda party of being too soft on extremists.
Last month, Interior Minister Ali Laryed said Tunisian police had arrested 16 Islamist militants who had been accumulating arms with the aim of creating an Islamic state.
They were linked to Al-Qaida in the Islamic Maghreb and had been planning to attack security headquarters, he said.