A firearms incident near to Wimbledon station caused police to temporarily shut down the station.
British Transport Police (BTP) and firearms officers were called the station at 4.27pm on Sunday, April 6.
There are no reports shots were fired or anyone was injured.
Police said two suspects, both 18-years-old, are in custody.
A third man had fled the scene before police arrived and officers are investigating to establish his whereabouts.
Wimbledon station reopened at about 6pm.