Israel launched a major attack on Iran, drawing their long-running shadow war into the open conflict in a way that could spiral into a wider, more dangerous regional war. The strikes early Friday set off explosions in the capital of Tehran as Israel said it was targeting Iranian nuclear and military facilities.

Iran began its retaliation campaign on Friday, after warning Israel that it would pay a “heavy price” for its earlier strikes.

Iran has long maintained that its nuclear programme is for civilian purposes only. It has several facilities around Iran, at least some of which have been targeted in the Israeli strikes.