Last week, Israel struck four buildings at the Isfahan nuclear site, among them a uranium conversion facility. The IAEA said there has been no sign of increased radiation at Isfahan, which is roughly 350 kilometers (215 miles) southeast of Tehran.

Russia warned against efforts to force a regime change in Iran and said it would react “very negatively” if Iran’s Supreme Leader Ayatollah Khamenei were killed, raising concerns of a broader escalation in the Israel-Iran conflict as European leaders came together with Iran on Friday for a diplomatic meeting.

Israel’s strikes on Iranian nuclear facilities have alarmed none more than Russia, the country that first brought nuclear power to Iran in defiance of Western objections. Decades of conflict with the West have united Iran and Russia,