SINGAPORE - A teenager who allegedly confessed in a video to sexually assaulting a girl has been offered bail of $50,000.

The 18-year-old Singaporean is said to have sexually penetrated a 14-year-old without her consent in Towner Road, near Serangoon Road, between 5pm and 9pm on Sept 21 last year.

The pair were friends then and a district court heard on Thursday (Jan 6) that the youth has been found to be fit to enter his plea. His medical report is pending.

Appearing in court via video-link, he cannot be named because of a gag order to protect the girl's identity, and his case has been adjourned to March.

He is accused of one count each of sexual penetration and being part of an unlawful assembly in which one person was armed with a baton, which is classified as a deadly weapon in court documents.

In an earlier statement, the police said: "(On Nov 22 last year, officers) received multiple reports after the man allegedly confessed to sexually assaulting a girl in a video that was uploaded on social media.

"The police commenced investigations immediately and arrested the man (the next day). Investigations are ongoing to determine if there are other victims involved."

The police said they take all reports of sexual assault seriously and will spare no effort to ensure that perpetrators are dealt with severely and in accordance with the law.

They added: "Victims of sexual assault are encouraged to come forward to report a crime. The police adopt a victim-centric approach to sexual crime investigations, and victims will be handled sensitively during the investigation process."

Separately, at around 10.20pm on Oct 4 last year, the youth is said to have been among 11 teenagers and men accused of unlawfully gathering on the second storey of a Woodlands Close building. They were between 15 and 24 years old.

They were allegedly there to assault a 17-year-old boy, who cannot be named under the Children and Young Persons Act to protect those below 18.

The names of the 11 alleged offenders have been redacted from court documents.

No details were given on the identity of the person who is said to have been armed with the baton.

If convicted of sexually penetrating a victim without consent, an offender can be jailed for up to 20 years and fined or caned.

Those convicted of being a member of an unlawful assembly and armed with a deadly weapon can be jailed for up to five years, fined or caned, or receive any combination of such punishments.