Tunisia bus bomber arrested, freed before attack

The suicide bomber in Tunisia who blew himself up in a bus packed with presidential guards on Tuesday had been arrested by police before on suspicion of jihadist ties but was released for lack of evidence, a security official said. Tunisia, one of the Arab world's most secular nations, is struggling to counter Islamist militancy since becoming a beacon of democratic change in the region after its 2011 uprising that ousted autocrat Zine Abidine Ben Ali. Houssem Abdelli, a street vendor from an impoverished neighbourhood of Tunis, detonated his explosives as presidential guards boarded a bus on Tuesday afternoon on one of the capital's main boulevards, killing 12 people. The potential missed opportunity to stop a suicide bomber - despite authorities finding jihadist literature in his house and neighbours noticing changes in his behaviour over the last few years - shows how security forces are struggling to prevent attacks. Abdelli's bus bombing follows massacres targeting a Sousse resort hotel and the Bardo national museum in Tunis earlier this year. Like other homegrown attackers before him and the Tunisians who left to fight for militant groups in Iraq and Syria, Abdelli appears...