The six were taken to a south-east London police station, the force spokesman said.
A 29-year-old man was arrested in the street in west London, a 21-year-old man and the women were arrested at a separate residential premises in west London, and three other men, aged 18, 24, and 26, were arrested in east London.
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.
Public safety remains our overriding concern.
More top news
Police say they have traced four drivers who are thought to have hit the woman, and added that a fifth vehicle may also have been involved.
Police are trying to trace two men after two homophobic attacks on gay men in Walthamstow
Two London Boroughs make it into the top 15 places to live in the UK.