Residents and visitors across the United Arab Emirates received a fresh emergency alert on their mobile phones stating that the situation in the country is currently safe.

The Qatar soccer federation postponed all tournaments and matches until further notice on Sunday amid global tensions following the U.S.-Israel strikes on Iran.

At least three people have been killed and 58 others injured in the United Arab Emirates since Iran began its retaliatory missile campaign in the Gulf following US and Israeli attacks, authorities said.

An enormous explosion rocked Iran's capital on Sunday as the Israeli military said it was targeting the heart of the city. Earlier, Iran fired missiles at targets in Israel and Gulf Arab states after vowing massive retaliation for the killing of Supreme Leader Ayatollah Ali Khamenei by the United States and Israel.

Oman on Sunday said an oil tanker in the strategic Strait of Hormuz came under attack, wounding four mariners on board.

Multiple explosions have been reported in key cities across the Gulf, Al Jazeera reported.

Iran has declared 40 days of public mourning following the reported killing of the country’s Supreme Leader Ayatollah Ali Khamenei, Al Jazeera reported citing Iranian state media.

Iranian media have confirmed that Iran’s Supreme Leader Ayatollah Ali Khamenei has been killed, Al Jazeera reported, citing Iranian news agencies.