According to RIA Novosti, the Russian cosmonaut Alexei Ovchinin informed specialists of the Mission Control Center near Moscow (MCC) about this.
It is specified that the alarm worked in the US segment of the ISS, and the increase in oxygen level occurred in the Russian module "Star".
Earlier on the ISS, the first tests of the FEDOR robot exoskeleton were launched.
On August 27, the Soyuz MS-14 spacecraft with the FEDOR robot successfully landed automatically at the second attempt at the ISS. The first docking was undertaken on August 24th. The attempt was unsuccessful due to a breakdown in the equipment of the Kurs docking system on the Search module of the ISS Russian segment.
Later, a video was published of the successful docking of the ship with the station.
In an interview with Nation News, Russian cosmonaut Pavel Vinogradov commented on the docking of Soyuz MS-14 with the FEDOR robot to the ISS.