The plant responsible for building the train that broke down Tuesday morning on the Moscow metro's Gray Line will be fined, a news report said.
One train lost power and stopped completely when the electricity supply was cut off on the track between the Serpukhovskaya and Tulskaya stations, forcing passengers on one train to wait in the tunnel for more than an hour.
As a result of the stoppage, eight passengers on the stricken train fell ill and required medical assistance, RIA-Novosti reported.
Responsibility for Tuesday's breakdown lies with "the train's manufacturer," Sobyanin said. "We will impose economic sanctions on it."
Sobyanin also confirmed that the incident on June 5, when a high voltage cable caught fire on the Sokolnicheskaya Line, was due to human factor.
Those deemed to have been responsible for the incident have already been fired, Moskovsky Komsomolets reported.
"They were not attentive enough. But we also need to understand the metro staff. They only have six hours at night to conduct maintenance works on this huge and technically complex system," the acting Mayor said.