One person was shot with a stun gun and Scotland Yard said armed officers were deployed during the arrests, The Guardian reported Thursday.
The five men and one woman were arrested on suspicion of committing, preparing or instigating acts of terrorism, police said. Officials said they believe the plot was inspired by al-Qaida ideology.
The arrests were not linked to any threat to the Olympic Games, but officials have said they would act faster than usual in thwarting any possible alleged plots ahead of the Games that begin in three weeks, The Guardian said.
"Searches under the Terrorism Act 2000 are being carried out at eight residential premises in east, west and north London and one business premises in east London," police said in a statement. "Public safety remains our overriding concern. Today's operation in London is not linked to the Olympic and Paralympic Games."