Police detained around 120 people in the northern Belgian city of Antwerp Saturday after scuffles at a protest against an anti-Islamic film that has sparked a wave of protests, local police said.

The protesters shouted anti-US slogans and praised the Prophet Mohammed. Footage aired by broadcaster RTBF also showed them burning the US flag.

The demonstration, which was organised by mass text messages, degenerated into clashes with police after officers blocked the protesters from moving to a main thoroughfare.

"We used pepper spray and batons, but no one was injured," the Antwerp police spokesman told the Het Laatste Nieuws daily.

Police said those arrested had been taken to police stations for identity checks and would be released later that evening.

A leader of the Islamist group Sharia4Belgium was among those detained, according to RTBF.

The low-budget US film "Innocence of Muslims", portrays Muslims and the Prophet Mohammed in insulting terms.

The protests, which started on Tuesday, have cost several lives and seen mobs burn US missions, schools and businesses as well as the embassies of some western countries.