Moscow (AFP) - Russian investigators said Wednesday they had detained two metro workers over a devastating crash in the Moscow subway that killed 22 people, as anger mounted over the tragedy.
City authorities declared Wednesday a day of mourning after the worst accident in the metro's eight-decade history, while Russians swapped stories of how the authorities had ignored their complaints about the famed transport system.
"Nightmare in the metro," declared mass-circulation daily Moskovsky Komsomolets, while opposition Novaya Gazeta newspaper added grimly: "Terminal point."
The disaster struck Tuesday during the morning rush hour on the crowded metro, one of the world's busiest, when a train braked sharply and three carriages derailed.
The health ministry said 22 people had now died and that of 150 people hospitalised, with several dozen in a serious condition.
Russian investigators said they had detained two metro workers for alleged safety breaches and that high-ranking officials could also be arrested.
The Investigative Committee, which reports directly to President Vladimir Putin, said it was holding a maintenance foreman Valery Bashkatov and his assistant Yury Gordov.
"The detained have already been questioned," the committee said, adding that they would soon be formally charged with safety breaches.
The train derailed in western Moscow between the recently built Park Pobedy station -- the deepest on the ornate marble-clad system at 84 metres underground -- and Slavyansky Boulevard.
Putin swiftly ordered a criminal probe.
The committee said the metro had since May been carrying out work to install a set of points -- a section of track allowing trains to change lines -- to launch a section of new rail.
The suspects had overseen the work, the committee said, adding that it believed "the works have not been conducted in a proper manner."
"A set of points was fixed in place with a piece of regular three-millimetre wire which snapped."
The committee indicated that higher-ranking officials could also be held responsible, saying it intended to probe "absolutely everyone involved in this tragedy".
- 'Lax oversight' -
Vyacheslav Babochkin, a former worker with Metrovagonmash, a manufacturer of subway carriages, said that instead of laying the blame on low-ranking workers, investigators should target senior officials.
"Only there you have to look for reasons for the tragedy," he told AFP, criticising a lax oversight of safety rules.
Babochkin, a former member of the factory's trade union, claimed he had been fired in January after he tried to draw the attention of his superiors to his concerns that faulty parts had been used to make train carriages.
"The busiest of the capital's transportation systems should undergo a comprehensive and open audit," liberal business newspaper Vedomosti said in an editorial.
Reports that the authorities repeatedly dismissed complaints about the Park Pobedy-Slavyansky Boulevard stretch have gone viral on social networks.
Sergei Molostvov, a 27-year-old Muscovite, sent a letter in June to the metro's administration, complaining of what he said were disturbing vibrations between the two stations.
After the crash he posted on Facebook what he said was a reply in which the subway insisted everything was fine with the tracks.
Molostvov told AFP the reply came just days before Tuesday's disaster.
"The metro is an affluent organisation, why can't they improve their services?" he added.
The subway, which first opened in 1935 under Stalin, transports nearly nine million passengers every day.