A group suspected of attempting to sell 100 counterfeit ventilators used to treat coronavirus patients have been detained after an armed confrontation outside Moscow, news outlets reported Wednesday.

The coronavirus pandemic has strained Russia’s healthcare system as infections have soared, with officials and healthcare workers pointing to widespread shortages in equipment such as ventilators. Russia has around 42,000-43,000 ventilators in its state hospitals, or an average of about 29 ventilators per 100,000 people.

“Suspects, including the group’s organizer, have been detained in the Moscow region for selling more than 100 counterfeit ventilators,” the state-run TASS news agency quoted an unnamed law enforcement source as saying.

The Life tabloid reported that eight people were detained after exchanging gunfire with officers in the Ramensky district 50 kilometers southeast of Moscow.

They were reportedly charged with fraud for attempting to sell the fake devices, which provide breathing support to patients whose lungs are failing, for 70 million rubles ($900,000).

Russia’s police spokeswoman Irina Volk told Interfax that seven people were detained, five of whom were placed under house arrest and two others banned from leaving Russia. She said authorities seized 1,500 20-year-old ventilators without certification documents.

Authorities have warned Russians of increased cases of fraud amid nationwide lockdown measures to slow the spread of Covid-19.

In a public address Tuesday in which he extended Russia’s “non-working” period to May 12, President Vladimir Putin promised to ramp up the country’s production of ventilators to 2,500 next month, up from 800 in April.