Police have charged a 36-year-old man in connection with a series of assaults in Adelaide's southern suburbs over the past week.

Jie Curtis was detained on Thursday evening and is expected to appear in court on Friday morning.

Police will allege five women have been stalked, threatened or assaulted, including a 16-year-old girl, in the city's southern suburbs since Sunday, according to police.

View photos South Australia Police officers arrest Jie Curtis at the Brighton Train Station in Adelaide. Photo: Supplied More

Earlier on Thursday an arrest warrant was issued for the man suspected of being the alleged knife-wielding stalker in Adelaide, as it was revealed a sixth incident had occurred.

However, police now say an incident at Plympton Park was likely not related to Curtis.

South Australia police said the Edwardstown man was spotted by a member of the public riding a train between Adelaide and Brighton just before 5pm.

View photos Police earlier released an image of Jie Curtis which must now be censored for legal reasons. Photo: SAPOL/Supplied More

Curtis was arrested without incident as commuters looked on.

He has been charged with three counts of attempt to detain a person, aggravated assault, one further count of assault and two counts of theft of a motor vehicle.

Police study maps of southern suburbs in hunt for serial stalker, after a 6th woman was approached @7NewsAdelaide pic.twitter.com/cfnfJrl40D — Elspeth Hussey (@ElspethHussey7) March 3, 2016

View photos

Police searched a unit block in the area after reports the allegedly stolen car he drove during the alleged attacks had been parked there.

"We have great concerns in relation to him," a spokeswoman told reporters on Thursday.