Iran’s supreme leader has warned the government would not “back down,” as rights groups fear the communications blackout in place could presage a brutal crackdown.

At least 544 people have been killed as security forces try to quash the unrest, activists say, with the true scale of the crackdown yet to become clear amid an internet blackout.

The Trump administration has surged immigration agents into Minnesota in what it has called the largest DHS operation ever.