At least six Russians have been arrested in Europe on international warrants since July, McClatchy Newspapers reported.
The arrests are part of a larger push on Russian hacking, according to a former high-ranking U.S. intelligence official who spoke to NBC News. Some of the hackers in the dragnet may have information on the election hacking.
Cyber experts have long reported that Russian security services use "patriotic" hackers to carry out attacks on intelligence targets. If a hacker refuses to help, it could lead to trouble with Russian authorities.
Pyotr Levashov, 32, was the latest Russian hacker arrested, just last week in Barcelona. Others were arrested in Prague, Thailand and Finland.
Tillerson Heads to Moscow as Tensions With Russia Rise
Before Secretary of State Rex Tillerson made his first diplomatic trip to Russia as tensions between the two countries increase, he blasted the country for its ties to the Syrian president.
"It is very important that the Russian government consider carefully their continued support for the Assad regime," Tillerson said in Italy at the G-7 summit, before heading to Moscow.