Elon Musk compared Canadian Prime Minister Justin Trudeau to Adolf Hitler in a tweet that seemed to support truckers protesting coronavirus restrictions and immediately caused a storm on Twitter.

Musk tweeted on Wednesday just before midnight in California and deleted the tweet by Thursday afternoon without explanation. He did not respond to a request for comment, according to Reuters.

Musk, chief executive of Tesla Inc, tweeted in late January of support for Canadian truckers who closed roads and bridges, drawing international attention to their opposition to health policies promoted by the Trudeau government.