Russia's State Investigative Committee said that the doctors had been detained on suspicion of causing death through negligence. It was not immediately possible to reach the doctors or their lawyers.
"As a result of the suspects' improper performance of their official and professional duties in organising and providing medical care... nine newborns who were born between 1 December 2025 and 12 January 2026 died," the Committee said.
The case, reported by state and independent news outlets, provoked widespread outrage in Russia.
Politicians, commentators and ordinary Russians asked how the country could hope to raise its birth rate - a priority set by President Vladimir Putin - if such tragedies were allowed to happen.
(Reporting by Reuters; Writing by Anastasia Teterevleva; editing by Guy Faulconbridge)
Russian President Vladimir Putin (R) visits the residence of Yaroslav Shvetsov, a doctor at the Tula Region Oncology Centre, in Tula, Russia, 02 February 2024. Vladimir Putin visit Tula to attends a meeting with participants of a forum titled 'All for a Victory!' EPA/ALEXANDER KAZAKOV / SPUTNIK / KREMLIN POOL MANDATORY CREDIT