The fighting between Israel and Iran intensified on Monday night, as both nations kept up their attacks, killing civilians and raising concern among world leaders that the biggest battle between old enemies could lead to a broad regional conflict.

The exchange of fire comes as talks on Iran's nuclear program in Oman between the U.S. and Iran were called off.

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

In response to evolving risks, the High Commission has facilitated the relocation of some Indian students to safer areas within Iran.

There will be no nuclear talks with Iran on Sunday, a senior U.S. administration official says, adding Washington still hopes Tehran will resume negotiations soon. “We remain committed to talks and hope the Iranians will come to the table soon,

Smoke and flames filled the sky over Tehran as Israel struck oil and gas facilities in the Iranian capital and targeted more nuclear facilities during attacks that carried on into Sunday after starting two days earlier.

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.