German police on Wednesday arrested four men who allegedly were planning attacks on U.S. military bases in the country. The suspects are believed to be members of the “Islamic State” (IS) terrorist organization.

The four suspects were originally from the central Asian nation of Tajikistan. A fifth man involved in the plot had already been held in detention for over a year.

“Targets for the attacks were supposed to be institutions of U.S forces in Germany or even individual people,” prosecutors said in a statement. “In particular, they planned a murder attack on one person who had made public comments that they viewed as being critical of Islam.”

In line with German privacy rules, the suspects were identified as Azizjon B., Muhammadali G., Farhodshoh K. and Sunatullokh K. The already detained individual, Ravsan B., was the reported leader of the group.

Prosecutors claimed the suspects pledged allegiance to IS in 2019, with the men receiving orders from leaders of the terrorist organization in Syria and Afghanistan.

IS first made major headlines in 2014, when the organization spread from Syria into Iraq, taking control of the city of Mosul. IS later carried out attacks internationally in November 2015 in Paris and March 2016 in Brussels.

The U.S., along with other nations such as France, formed a global coalition against the terrorist group, with the organization having lost most of its territory by March 2019.

In October, President Trump announced the death of the group’s leader, Abu Bakr al-Baghdadi, with the organization now being led by Abu Ibrahim al-Hashimi.