Two men handed themselves in to police on Saturday, a day after an outbreak of mass panic in a busy area of central London, British Transport Police said.
"We appealed for information following an incident at Oxford Circus yesterday. Since the appeal two men, aged 21 and 40, attended a police station voluntarily and were interviewed," police said on Twitter.
The investigation was ongoing, police added.
Pandemonium broke out at about 1630 GMT on Black Friday, one of the year's biggest shopping days, following reports of gunfire at two London Underground stations near Oxford Street, a busy shopping area.
But police said there was no evidence of any gunfire, later adding that "an altercation erupted between two men on the platform" at Oxford Circus station.
British Transport Police released two CCTV images of the men and said they would like to speak to them and anyone else who may have information relevant to the incident.
Eight people were taken to hospital for minor injuries suffered in the panic while a ninth was taken to a major trauma centre for leg injuries. Seven people were treated by paramedics at the scene, the London Ambulance Service said.
Police said they had responded in line with procedures for a terrorist incident, conducting "a full and methodical search of the station and Oxford Street."