Thailand has joined the international community in condemning a terror attack on a subway train in St Petersburg which killed at least 11 people.
Thailand condemned "this senseless and horrific act of violence" and vowed to cooperate with Russia and other countries to fight "violence and acts of terrors", Prime Minister Prayut Chan-o-cha said in a message to his Russian counterpart Dmitry Medvedev on Tuesday.
The bomb on Monday also injured about 50 persons.
The Thai embassy in Moscow said no Thais were reported injured and advised Thai citizens in St Petersburg and other big cities in Russia to avoid travelling to places popular for public gatherings.
Kyrgyzstan's State Committee for National Security said in a statement on Tuesday that the man behind the bombing is a Kyrgyz-born Russian national. The intelligence agency said it is cooperating with Russian authorities to help the investigation.
In the past two decades, Russian trains and planes have been frequent targets of attack, usually blamed on Islamic militants.
Neither authorities in Russia nor in Kyrgyzstan have specified whether the attack was a suicide bombing or whether the bomber got away.
The Interfax news agency on Monday said authorities believe the suspect, a 23-year old who came from ex-Soviet Central Asia and was linked to radical Islamic groups, carried the explosive device onto the train in a rucksack.
Within two hours of the blast, authorities had found and deactivated another bomb at another busy station, the anti-terror agency said. That station is a major transfer point for passengers on two lines and serves the railway station to Moscow.
The entire St Petersburg subway system was shut down and evacuated, but partial service resumed after about six hours.
Reuters video