MOSCOW, March 7 (Xinhua) -- Dozens of Chinese passengers were detained at an airport in Moscow on Friday for bringing food materials which Russian Customs officials believed to be drugs, according to the Chinese Embassy to Russia.

The Chinese passengers are employees of a company in northeast China's Heilongjiang Province and what they brought with them is actually bittern, a kind of material used to make Chinese food tofu, the embassy said.

Russian airport officials have been suspicious of the substance. Tests and analysis of their chemical composition are underway.

Earlier reports from Russian media claimed that 34 Chinese citizens were detained at the Sheremetyevo airport in northwestern Moscow when they arrived on a flight from Beijing with 230 kilograms of methamphetamine found in their luggage.