The head of Russia's Federal Security Service (FSB) has announced the arrests of eight people suspected of involvement in the St Petersburg metro bombing.
In a meeting with the National Antiterrorism Committee, Alexander Bortnikov announced six people had been apprehended in Moscow, while two had been taken into custody in St Petersburg.
He added that security service officers had also confiscated a large cache of weapons from the eight people arrested.
The FSB Chief stressed there had to be more stringent measures at Russia's borders in order to prevent terrorists from infiltrating the country, saying the attack on St Petersburg demonstrated a failure to meet potential terrorist threats.
At least 14 people were killed when a bomb went off on the metro at Sennaya Ploshchad station on April 3.