Israeli forces and the pro-Iranian militia Hezbollah engaged in massive exchanges of fire across the border between Israel and Lebanon early on Sunday. Hezbollah said it had fired hundreds of missiles at Israel in retaliation for the killing of one of its commanders in Beirut, as Israel said it carried out dozens of pre-emptive airstrikes in southern Lebanon. Hezbollah said more than 320 missiles had been fired at Israeli military bases. “Our military operation for today has been completed, thanks to God Almighty,” the Islamist group said. Israel put the number at 200 missiles and about 20 dro…