DUBAI, United Arab Emirates (AP) — Israel unleashed airstrikes across Iran for a third day and threatened even greater force as some Iranian missiles evaded Israeli air defenses to strike buildings in the heart of the country. Planned talks on Iran’s nuclear program, which could provide an off-ramp, were called off. The region braced for a protracted conflict after Israel’s surprise bombardment of Iran’s nuclear and military sites on Friday killed several top generals and nuclear scientists, and neither side showed any sign of backing down. Israel reportedly targeted a gas installation, raising the prospect of a broader assault on Iran’s heavily-sanctioned energy industry that could affect global markets.