Last week, prosecutor Daniel Suneson decided to charge Mayers and two others with assault, which carries a maximum penalty of two years in prison.

When the trial opened on Tuesday the rapper, who has spent weeks in custody, pleaded not guilty to assault saying he acted in self-defence.

Much of the trial has centred around analysing videos and whether bottles had been used as weapons during the alleged assault.

The videos include one published by US celebrity news outlet TMZ, where the rapper can be seen throwing a young man to the ground and apparently aiming several punches at him while he is down.

The court was also shown videos posted to the artist's own Instagram, purporting to show the lead up to the brawl, which the prosecution argued had been heavily edited.

- 'Self defence' -

Mayers' lawyer Slobodan Jovicic argued that the rapper's actions were the result of the plaintiff and his friend showing "a threatening, aggressive and deeply provoking behaviour".

"He admits that he threw the plaintiff on the ground, that he stepped on his arm and punched or pushed his shoulder," Jovicic told the court, saying it was a case of "self-defence".

On Thursday, the trial will resume at 9:00 am (0700 GMT) and the court will hear Mayers' own testimony. The trial is scheduled to conclude with closing arguments on Friday.

After the trial has ended the court will announce when it will be able to render a verdict and also decide whether the accused should be kept in custody in the meantime.

Mayers was remanded in custody while the case was being investigated as he was considered a "flight risk".

Fans, fellow artists and US Congress members have been campaigning for his release.

An online petition called #JusticeForRocky has garnered more than 640,000 signatures. Social media campaigns have urged fans to boycott Swedish brands such as IKEA.

US President Donald Trump has repeatedly called for the rapper to be freed, drawing complaints of interference from Swedish politicians.

Robert C. O'Brien, US Special Presidential Envoy for Hostage Affairs, had been sent to attend the trial.

"The president asked me to come here and support these American citizens and we're working to bring them back as soon as possible," O'Brien told AFP.