Three released after Melbourne terror raid

Three of five teenagers arrested in pre-dawn raids in Melbourne have been released while two remain in custody, with police alleging the pair were planning an imminent terror attack on Anzac Day events.

Eighteen-year-old Sevdet Besim, from Hallam, has been remanded in custody after appearing briefly in Melbourne Magistrates Court on Saturday charged with conspiring to commit terrorist acts.

Another 18-year-old from Hampton Park is also expected to be charged with offences relating to preparing for a terrorist act and remains in custody.

The three other men were released after being questioned for most of Saturday.

It's expected one of them - a third 18-year-old - from Narre Warren will be charged on summons with weapons offences.

The two other Narre Warren men, aged 18 and 19, have been released pending further enquiries.

Dubbed Operation Rising, more than 200 heavily-armed officers swooped on the city's southeast about 3am on Saturday, executing search warrants in Narre Warren, Hampton Park, Hallam and Eumemmerring, arresting the men and seizing knives and swords.

Authorities have refused to give details of the alleged plot but say police at Anzac activities around Melbourne were the immediate target.

It's also believed the attacks were Islamic State-inspired.