The US military writes on its Twitter that the incident was recorded between 7:02 and 8:51 Moscow time. As a result, 65 fragments were discovered. The explosion was not caused by a collision with another object. The fact that the wreckage can harm satellites is not said.
In the military catalog of space objects, the exploded tank bears the number 37756, its international designation is 2011-037B. Previously, the object was in orbit with a minimum altitude of 422 km and a maximum of 3606 km.
Frigate-SB is a modification of the Frigate booster unit with a resettable tank unit. It is designed for medium and heavy missiles. In 2011, with the help of Frigate-SB, the Spektr-R astrophysical observatory was put into orbit.
Also in March 2020, the Soyuz-2.1b launch vehicle launched 34 British OneWeb satellites into orbit with the help of Frigate-SB. The first six Roskosmos satellites were launched at the end of February last year from the Kourou Cosmodrome in French Guiana, the Soyuz-ST-B launch vehicle with the same upper stage. In preparation for the launch, it turned out that Fregat-SB had a leak in the seam of the helium supply pipe to the fuel tanks.
At the end of 2017, after the launch of Soyuz-2.1b from the Vostochny cosmodrome, the Fregat upper stage was in the zone of lack of radar, the meteorological satellite Meteor-M did not communicate. Later in the "Roskosmos" explained that he fell into the ocean.
Also, with the launch of Angosat, the first communications satellite of Angola launched from Baikonur, specialists could not establish communication after the rocket entered orbit. The satellite got in touch at the first moment after separation from the Frigate upper stage, then telemetry information ceased to be received. The satellite was silent for several months, but Roscosmos was in no hurry to recognize it as lost - recognizing the loss of the device would mean that the state corporation should make a new satellite for Angola.
Note that since 1961, about 250 destruction of space objects (active and inactive satellites, spent stages of launch vehicles and booster blocks) were recorded in orbit.