Ed Sheeran’s tour of North and South America was plunged into chaos Tuesday when four of his supporting acts — including his touring band — abruptly quit in solidarity with the rapper Macklemore, who was dropped for making pro-Palestinian comments onstage.

Hours after Sheeran posted on social media about Macklemore’s ouster and attributed the decision to the tour’s promoters, Irish acts Aaron Rowe and Beoga, the Danish band Lukas Graham, and Finneas posted on Instagram that they were leaving the tour.

Rowe and Lukas Graham would have been replacements for Macklemore on Sheeran’s remaining U.S. dates, while Beoga was serving as Sheeran’s touring band. Finneas, who is Billie Eilish’s brother and musical collaborator, was due to tour with Sheeran in South America later this year.

“Artists must not be silenced when they speak up for the oppressed,” Finneas said on Instagram. “I have decided to withdraw from my upcoming tour dates with Ed Sheeran. I stand with Palestine and its people.”

The moves by his fellow artists put enormous pressure on Sheeran, who has tried to avoid politics and taking a side in the Gaza conflict, arguing that his fans don’t come to his shows to hear politics.

Rowe and Beoga each cited their country’s history in their statements explaining their decision. “We are Irish people who understand colonialism. As founding members of the Irish Artists for Palestine movement, we are committed activists for justice and will continue to be,” Beoga said.

Rowe called Sheeran a friend and said the British singer-songwriter changed his life. “But as Irish people we know all too well about genocide, forced famine and violent occupation,” he said, adding that he couldn’t “stand by and allow billionaires to use their position of power to silence the rightful voices of those who speak up.”