Iran has escalated its internal crackdown, executing suspected spies and arresting over 700 people in just 12 days amid its conflict with Israel.

Mere hours after a fragile cease-fire between Israel and Iran went into effect, Israel ordered fresh attacks on Tehran after the Israeli military detected missiles launched from the Islamic state.

A senior nuclear scientist was among nine people killed in an overnight Israeli strike in northern Iran, Iranian officials and state TV have said, hours before a ceasefire ending 11 days of conflict took effect.

It remained to be seen whether the attack would ignite a regional war or provide the U.S. and Iran with an off-ramp from their intensifying confrontation.

Iran launched a missile attack on Al Udeid Air Base — the largest U.S. military installation in the Middle East, which President Donald Trump visited just last month — after the U.S. carried out a series of bombings against three nuclear sites in Iran over the weekend.