A Russian Jewish leader and his assistant were hospitalized after a package sent by mail exploded in his office.

The package exploded early Monday morning in the office of Mikhail Skoblionok in Kazan in Russia’s Tatarsan region, Radio Free Europe reported.

Skoblionok is president of the Jewish Cultural Autonomy, a local organization he has led since 2008.

He and his assistant were hospitalized with burns and eye injuries, according to the report. It is not yet clear whether the attack was criminally motivated, or a hate crime. It is being investigated as an attempted murder, the regional branch of the Investigative Committee said.

Skoblionok also goes by the last name Abramovich, according to a statement from the World Jewish Congress.

“I was shocked and horrified to hear about today’s explosion targeting the head of the Jewish community in Kazan, Russia. I wish to extend my best wishes to Mr. Abramovich and his family and hope for a speedy recovery,” WJC CEO and Executive Vice President Robert Singer said in a statement. “I have known Mr. Abramovich for more than 25 years, and have seen that the rebirth and well-being of his community was, and is, in large extent due to his personal involvement. We fully trust that the local authorities are doing all in their power to investigate and ensure that the perpetrators behind this evil and sickening act are brought to justice as soon as possible.”