Iran and Israel exchanged missile strikes on Saturday as the conflict sparked by Israel’s attack on its regional rival’s nuclear programme entered a second day.

Prime Minister Benjamin Netanyahu of Israel presented Iran’s sophisticated ballistic missiles as a critical threat to Israel’s survival.

Iran and Israel exchanged more airstrikes overnight Friday and continuing late Saturday after Israel mainly attacked Iranian nuclear and military targets two days ago.

The Lebanese militant group Hezbollah was long considered Iran’s first line of defense in case of a war with Israel.

The two sides were scheduled to meet for a sixth round of negotiations on Sunday. Oman, which was set to host the talks, said on Saturday that this round had been canceled.

Israel has carried out a strike against Iran. The strike came hours after U.S. and Israeli officials had warned one was imminent. Follow along for live updates, news and analysis.

Iran has warned it will ramp up its nuclear activities after the United Nations nuclear watchdog’s 35-member board of governors adopted a resolution Thursday declaring it in breach of its non-proliferation obligations.

The decision comes as officials say they believe that Israel is preparing to launch a military attack on Iran. Tehran condemned the vote.