MOSCOW, May 23. /TASS/. An unknown perpetrator has captured at least five hostages at the Alfa-Bank office on Zemlyanoy Val street in Moscow and threatens to blow up the building, an emergency services source told TASS.

"An unknown perpetrator captured five hostages at the Alfa-Bank office […] and threatens to blow up the building. There are at least five hostages in the building," the source said.

A Prompt Response Special Team (SOBR) of the Russian National Guard has been dispatched at the site of a hostage situation in an Alfa-Bank office, a law enforcement source told TASS.

"The SOBR has been dispatched at the site. The law enforcement is ready to begin negotiations. According to the preliminary information, the perpetrator hold an unidentified package in his hands," the source said.

A portion of Moscow’s Verknyaya Syromyatnicheskaya street between Zemlyanoy Val street and the Suzdalsky avenue was closed over a hostage situation in an Alfa-Bank office, Moscow Transport Informational Center told TASS.

The man demands a large sum of money from the Bank’s administration, a source in emergency services told TASS.

"The perpetrator has got into a difficult life situation. He demands a large sum of money from the Alfa-Bank administration. According to the preliminary data, the man works as a courier, delivers food," the source said.