Four pro-Palestine protesters were arrested for climbing the roof of Australia’s Parliament House in a security breach condemned by lawmakers, on the same day a ruling party senator quit over the government’s stance on Palestine, Reuters reports.

Police and security advised people not to walk directly under the protest at the main entrance to the building, while more were seen on the roof attempting to remove the protesters.

The protesters packed up their banners before being led away by waiting police at around 11:30am local time (01:30am GMT).

The four were arrested and charged with trespassing, and have been banned from the grounds of parliament for two years, a spokesperson for Australian Capital Territory police said.

Prime Minister Anthony Albanese condemned the protests. “Those responsible should feel the full force of the law. Peaceful protest has an important place in our society, but this was not a peaceful protest,” he said.

The Speaker of Australia’s lower house Milton Dick said he had ordered an investigation into how the security breach occurred.

Fatima Payman, a senator in the ruling Labour Party, quit the party on Thursday to sit as an independent after she was suspended for voting for a motion backing Palestinian statehood.