Republican nominee Donald Trump started a new wave of attacks against Muslim immigrants on Thursday, urging his supporters to support his ban of refugees from “terrorist nations” from coming into the United States.

“We are letting people come in from terrorist nations that shouldn’t be allowed because you can’t vet them,” Trump said at his campaign rally in Portland, Maine.

“You have no idea who they are. This could be the great Trojan horse of all time,” he warned.

Donald Trump climbed to the top of his party to become the Republican presidential nominee base on his anti-immigration platform. He continues to push the idea that terrorists groups like ISIS are trying to sneak into the country.

“This is a practice that has to stop, „Trump said about letting in refugees.

He referred to the “thousands” of Somali immigrants that have congregated in Maine and other states, causing several problems in the state.

Trump said the system of resettling refugees were “having the unintended consequence of creating an enclave of immigrants with high unemployment that is both stressing the state’s… safety net and creating a rich pool of potential recruiting targets for Islamist terror groups.”

He then named several immigrants from Muslim countries like Iraq and Pakistan who have arrested for terrorist activities including violent attacks and supporting terror groups.

“We’re dealing with animals,” he said angrily.

“Hillary Clinton wants to have them come in by the hundreds of thousands,” Trump told a crowd of jeering supporters.