German citizens were asked by their country on Thursday to leave Iran, amid the ongoing crackdown on protests.

“German nationals are asked to leave Iran. For German nationals there is a concrete risk of being arbitrarily arrested, interrogated and sentenced to long prison terms,” a Foreign Ministry statement said.

“Above all, dual nationals who have Iranian as well as German citizenship are at risk,” it added.

The statement noted that in the recent past, “there have been a large number of arbitrary arrests of foreign nationals.”

German-Iranian ties have deteriorated in recent weeks as Berlin has adopted a tough stance on the security crackdown on protests in Iran.

Iran has been rocked by protests since mid-September after the custodial death of 22-year-old Mahsa Amini, who was arrested by the country’s morality police for allegedly violating the Islamic dress code.

German Foreign Minister Annalena Baerbock has also pointed to EU plans to place Iran’s Revolutionary Guards on the terror list for its role in suppressing the protests.

There could be “no “business as usual” in bilateral relations,” Baerbock said last week, adding her country would tighten entry restrictions on Iranians beyond an already announced EU sanctions package in response to the human rights situation in the country.

Iran’s ambassador to Germany has been summoned at least three times to the Foreign Ministry since the start of the unrest in the country.

Tens of thousands of people also took to the streets of Germany over the past seven weeks to voice solidarity with the protest movement in Iran.