U.S. singer Katy Perry and other celebrities urged Americans to contact lawmakers to voice opposition following the killing of two citizens by federal immigration officials, amid an immigration crackdown launched by President Donald Trump’s administration in Minnesota.

Perry asked her followers on Monday to write to U.S. senators and call on them to oppose funding for Immigration and Customs Enforcement (ICE), an agency under the Department of Homeland Security.

The killing of Rene God sparked criticism on social media, with opponents saying the incident highlighted the consequences of the administration’s hardline immigration policies.

The Department of Homeland Security did not immediately respond to requests for comment.