Dozens of musicians and panelists have withdrawn from the South by Southwest Conference and Festivals in Austin, Texas, to protest sponsorship by the U.S. Army and defense companies as pressure grows against the U.S. military’s support of Israel’s war against Hamas in Gaza.

More than 80 artists and panelists at SXSW had joined the boycott by Wednesday, according to one of the organizers, the Austin for Palestine Coalition.

Ibrahim Batshon, a Palestinian American and the chief executive of BeatStars, a digital music-licensing platform and longtime sponsor of the music and technology festival, withdrew from SXSW after learning of the increased involvement this year of the U.S. Defense Department. The United States is the largest supplier of military equipment to Israel.

Mr. Batshon, who is Palestinian American and is known as Abe, said that six of his family members were killed in a bombing in November while taking refuge at a church in Gaza City.

“When I found out they were going to have a massive presence at a music festival where creatives and young people get together to collaborate and connect, I couldn’t get behind that,” he said.

Lambrini Girls, a queer indie rock duo from Brighton in Britain, was among many of the performers who have made statements on social media citing sponsorship by military defense contractors like Collins Aerospace, RTX and BAE Systems as the reason they withdrew from the festival.