The arrest and remand of 113 people for allegedly threatening parliamentary democracy on Friday is "preposterous" because they were merely listening to music, Lawyers for Liberty said.

The youths were arrested during the event 'Party Tonight, Revolution Tomorrow' at independent music venue Rumah Api in Ampang, Selangor, on the eve of the Bersih 4 rally

"It is quite incomprehensible how the police came to the conclusion that youths enjoying live underground music can be anything criminal much less, be arrested and remanded for several days for activity detrimental to parliamentary democracy, unlawful assembly and sedition.

"Surely the police cannot be so literal-minded and irrational to base the raid solely on the theme of the event and seriously thought that the gig-goers would go on a 'revolution' on the next day?" Lawyers for Liberty executive director Eric Paulsen asked.

He also condemned the magistrate for "rubber stamping" the remand application under sections 124B and 143 of the Penal Code and section (4)(1)(b) of the Sedition Act, when "there was no merit" for the case.

Section 124B of the Penal Code, which deals with activities detrimental to parliamentary democracy, carries the most severe penalty. If charged and found guilty, the youths can be sentenced to a maximum of 20 years’ jail.

Paulsen believes the arrests were "aimed at punishing youths for participating in any Bersih-related events, no matter how remote".

"We call on the police to go back to basics – to be a professional, impartial and competent police force in maintaining law and order, preventing and detecting real crimes and apprehending real criminals rather than be concerned with frivolous matters like youths enjoying underground live music," he said.

He also urged police to return all equipment and materials seized be returned to the rightful owners.

Police released all of those arrested except for two foreign nationals on Monday. Another detainee was released on Tuesday.

Five foreigners from the United States, Germany, Spain, Indonesia and the Philippines were among those arrested.