By Tarek Amara TUNIS (Reuters) - Tunisian authorities said on Wednesday a suicide bomber wearing a vest packed with plastic explosive blew up a presidential guard bus a day earlier, killing at least 12 troops in an attack claimed by Islamic State militants. Tuesday's explosion on a main boulevard in the capital drove home the vulnerability of Tunisia to Islamist militancy, following assaults on a seaside tourist hotel in June and the Bardo Museum in Tunis in March also claimed by Islamic State. One of the Arab world's most secular nations, Tunisia has increasingly become a target for militants after being hailed as a beacon of democratic change in the region since its 2011 uprising ousted autocrat Zine Abidine Ben Ali.
By Nick Tattersall and Vladimir Soldatkin ISTANBUL/NIZHNY TAGIL, Russia (Reuters) - Russia sent an advanced missile system to Syria on Wednesday to protect its jets operating there and pledged its air force would keep flying missions near Turkish air space, sounding a defiant note after Turkey shot down a Russian fighter jet. The downing of the jet on Tuesday was one of the most serious publicly acknowledged clashes between a NATO member and Russia for half a century, and further complicated international efforts to battle Islamic State militants in Syria. President Tayyip Erdogan made no apology, saying his nation had simply been defending its own security and the "rights of our brothers in Syria".
The Turkish military on Wednesday released what it said was an audio recording of a warning to a Russian fighter jet before it was shot down near the Syrian border. The surviving crew member of the Russian fighter jet shot down by Turkey on Tuesday said earlier the plane received no warnings from the Turkish Air Force and did not fly over Turkish air space, Russian news agencies reported.
TUNIS (Reuters) - Tunisia will close its border with Libya for 15 days, hire 6,000 more recruits for security forces and act to protect itself against Tunisians returning from conflict zones like Syria, the president's office said on Wednesday. The measures were announced a day after a suicide bomber blew himself up on a bus carrying presidential guards in the center of the capital Tunis, killing 12 people and forcing the government to impose a state of emergency. (Reporting by Tarek Amara; Writing by Patrick Markey; Editing by Mark Heinrich)