AlQa'dah 9, 1433, Sep 25, 2012, SPA -- More than 22,000 schoolchildren have been evacuated from schools in Nizhnevartovsk in the Khanty-Mansiysk autonomous district following an anonymous warning about a bomb planted in one of the school buildings. A youngster telephoned police on Tuesday, saying that a bomb was planted in one of the schools in Nizhnevartovsk. The caller did not specify the number of the school under threat. The authorities of Nizhnevartovsk decided to evacuate students from all the educational establishments. All the city police were put on alert. Traffic police have cordoned off all roads leading to schools. Experts with sniffer dogs have been searching all the school buildings, Itar-Tass reported.