Israel appeared to be expanding its air campaign against Tehran five days after its surprise attack on Iran’s military and nuclear program, as U.S. President Donald Trump posted an ominous message warning residents of the capital to evacuate.

Israel has launched a series of strikes against Iran, targeting the country’s nuclear program and other military infrastructure. Iran has launched its own strikes in retaliation.

Israel attacked Iranian state television after Iran fired another wave of missiles at Israel on the fourth day of open warfare between the regional foes.

The conflict between Israel and Iran has forced many countries in the Middle East to close their airspace, as Israeli jets and Iranian exploding drones and missiles fly over their night skies.

When Israel launched its series of strikes against Iran last week, it also issued a number of dire warnings about the country’s nuclear program, suggesting Iran was fast approaching a point of no return in its quest to obtain nuclear weapons and that the strikes were necessary to preempt that outcome.

At least 24 people have been killed in Israel as Iran launched retaliatory airstrikes targeting civilian areas. A U.S. Embassy branch in Tel Aviv suffered minor damage.

Israel stunned Iran last week with an intelligence and military operation years in the making that struck high-level targets with precision.