Russian authorities have detained hundreds of people in the wake of two terrorist attacks that killed 34 people in Volgograd.
Russian news agencies quoted the regional Interior Ministry as saying some 700 people, including many migrants from Central Asia and Russia's North Caucasus region, were detained following the December 29-30 attacks.
The authorities are still investigating the attacks carried out by suspected suicide bombers at the city's railway station and a public trolleybus, but Russia's Federal Security Service has said it strongly suspects North Caucasus Islamist militants carried out them out.
The policeman who tried but failed to stop the suicide bomber at the railway station on December 29 was buried in Volgograd on January 2.
Dozens of people were injured in the attacks, and several remain in serious condition in hospital.
Based on reporting by Interfax and ITAR-TASS