East Asian countries, including Japan, have become increasingly concerned with the Islamic State group following the killing and kidnappings of several Japanese nationals, Japan Times reported Friday. There were particular fears that the extremist group, also known as ISIS, could target embassies throughout the Middle East, a defense review published annually by the Japan Defense Ministry's research wing indicated.

“ISIL is threatening the security of East Asia, including Japan, by targeting the Asian people and Asian embassies in the Middle East, showing its ambition for territorial expansion, as well as recruiting foreign fighters from Asian countries,” the East Asia Strategic Review by the National Institute for Defense Studies Japan said, using an alternative acronym for the terrorist organization, the Japan Times reported.

It was the first year ISIS was allocated an entire chapter in the review, highlighting the expanding threat the group is thought to pose. The release comes days after attacks targeted a subway station and airport in Brussels, resulting in at least 31 civilians dead and some 300 injuries. ISIS claimed responsibility for those attacks, and Thursday, the group’s propaganda wing released a video celebrating the violence and extolling the virtues of fighting the West.

It also comes a week after a Japanese journalist believed to have been captured in Syria a year ago appeared in a video online. Junpei Yasuda, who delivered an emotional message to his family in the video, is believed to be held by the al Qaeda-affiliated Nusra Front. Last year, two Japanese nationals — journalist Kenji Goto and a security contractor, Haruna Yukawa — were executed by ISIS.

The report also included fears that the group was expanding into China, adding that its territorial claims appeared to including the Xinjiang northwestern, predominantly Muslim province. Many Uighurs are believed to have joined ISIS, and some have carried out small-scale attacks within China, but human rights advocates have also alleged that the Chinese government has inflated the threat to crack down on separatists.

Although ISIS has carried out a number of major attacks overseas in recent months, the group has steadily lost its grip of territory within Syria and Iraq. Since its peak in 2014, militants may have lost as much as 40 percent of territory in Iraq and 20 percent in Syria. At the same time, affiliates of the group have seen gains overseas, particularly in Libya.