Story highlights People in United Kingdom, Germany and United States among those threatened

Advocacy group calls it "an unacceptable attack on freedom of expression"

Four secular bloggers have been brutally killed in Bangladesh this year

(CNN) Islamic extremists in Bangladesh appear to be taking their war on secular writers and bloggers beyond the South Asian country's borders.

A hit list purporting to be from the militant group Ansarullah Bangla Team has been sent out threatening people in Europe and North America.

"Let Bangladesh revoke the citizenship of these enemies of Islam," a statement accompanying the list says. "If not, we will hunt them down in whatever part of God's world we find them and kill them right there."

The list contains nine people in the United Kingdom, eight in Germany, two in the United States, one in Canada and one in Sweden. CNN isn't reporting any of the names on the list.

'An unacceptable attack on freedom of expression'