Israel launched strikes on Iran’s capital early Friday, with explosions booming across Tehran as Israel said it targeted nuclear and military sites.

The Israeli military says it has “full aerial operational control” over the Iranian capital of Tehran, as the deadly conflict between the two enters its fourth day. Overnight explosions also rocked Israel’s port city Haifa and the city of Tel Aviv,

The IDF says Iran has launched about 100 drones towards its territory and says it killed Revolutionary Guards commander Hossein Salami in overnight strikes.

Iran quickly retaliated by sending a swarm of drones at Israel, and Supreme Leader Ayatollah Ali Khamenei warned of “severe punishment.”

As tensions escalate, Iran has developed a range of calculated options to retaliate if attacked, raising the stakes for the entire region.

The strikes are a sign of Israel’s shift away from restraint, containment and short wars, and toward using force to project power across the Middle East.