British trip-hop band Massive Attack has been barred from performing in Singapore after an investigation found two members unfurled a Palestinian flag during a concert, police said.

Singapore, known for its tough laws on public speech and assembly, bans the open display of all foreign flags, national emblems or banners without a permit.

Two band members who held the flag on stage during a concert on Wednesday were also banned from re-entering Singapore and issued with warnings, police said in a statement late on Friday, without naming the pair.

The concert promoter had not responded to an AFP request for comment at time of publication. The band had not issued a public comment.

A video circulating online showed two Massive Attack members on stage unfurling a Palestinian flag to loud, prolonged cheers from the audience.

After concluding their investigation and in consultation with state prosecutors, police said they “administered stern warnings to both men” and barred them from coming back to the city-state.

The media regulator was also probing possible breaches of licensing conditions.

“Notwithstanding the event organiser’s prior acknowledgment of the licence conditions, during the performance, two band members held a foreign flag on stage, and one of them also shouted ‘Free Palestine’,” police said.

The media regulator “will also not grant any future application for performances by the band in Singapore in view of the entry ban”, police said.

The band is known for its criticism of Israel’s military actions in Gaza and has used its popularity to support the Palestinian cause.

In April, frontman Robert Del Naja was among more than 200 people arrested at a protest in London’s Trafalgar Square in support of Palestine Action, an activist group banned by British authorities.

Singapore is a major concert hub for south-east Asia, having hosted multi-night performances by Taylor Swift, Coldplay, Ed Sheeran and Bruno Mars.

The police urged the public, including foreigners, “to refrain from importing foreign politics as this can undermine our social cohesion and the rule of law”.