The United States launched an eleventh consecutive night of military strikes against Iran, with explosions reported in the northwestern region of Tabriz as well as in Mahshahr in the country's southwestern Khuzestan province.
US Central Command (CENTCOM) said the strikes began at 7 pm Eastern Time (2300 GMT) on Tuesday and stated they were intended to continue degrading Iran's ability to threaten commercial shipping in the Strait of Hormuz.
If confirmed, the reported strike near Tabriz would mark a departure from the recent focus on southern Iran and areas surrounding the strategic waterway.
Residents also reported air defence activity in northeastern Tehran, according to the Fars news agency.
CENTCOM said the United States had redirected eight commercial vessels and disabled one as part of enforcing its naval blockade of Iran.
The blockade was reinstated earlier this month after previously being lifted in June.
The latest military activity follows the breakdown of a June 17 memorandum of understanding between the United States and Iran, after which attacks resumed as both sides competed for control of the Strait of Hormuz.
Iran's Khatam al-Anbiya Central Headquarters said any US attack on the country's nuclear facilities would be considered an expansion of the war.
The statement came after US President Donald Trump threatened to "heavily" attack Iran's Pickaxe Mountain, which has been reported to contain new Iranian nuclear facilities.
The United Nations expressed concern over the expanding conflict, with spokesperson Stephane Dujarric saying Secretary-General Antonio Guterres was deeply concerned by the continuing military escalation between the United States and Iran.
According to the UN, the crisis has affected Iran, Bahrain, Jordan, Syria, Iraq, Saudi Arabia, Yemen, Qatar, Kuwait and the United Arab Emirates.
Guterres also voiced concern over attacks on civilian infrastructure, including power and desalination facilities, saying, "Such attacks are unacceptable and must stop immediately."
Meanwhile, Kuwait continued electricity rationing after Iranian strikes affected power infrastructure, while Qatar condemned attacks on Bahrain, Jordan and Kuwait, including the reported targeting of the Kuwaiti tanker Kaifan in the Strait of Hormuz, and called for an immediate halt to military operations.
Analyst Negar Mortazavi said there remained room for diplomacy but argued Iran wanted the terms of the previous memorandum of understanding to be honoured before negotiations could advance.