TEHRAN/MANAMA/UNITED NATIONS/CAIRO - Multiple explosions were heard early Monday in the port cities of Sirik, Bandar Abbas and Jask, all in southern Iran's Hormozgan province, Iran's state-run Press TV reported.

Initial reports showed that a telecommunications tower near Sirik was hit, the same site targeted in previous attacks, Press TV said on social media platform X.

So far there has been no report of civilian casualties, it said, citing the provincial governor's office.

Minutes after the explosions, the US Central Command said on X that its forces began launching more strikes against Iran "to continue degrading their ability to attack civilian mariners and commercial ships freely transiting the Strait of Hormuz."

On Sunday, the United States and Iran traded another round of attacks over navigation in the strait despite a memorandum of understanding signed by the two countries in mid-June.

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The US Central Command said in a post on X early Sunday that its forces had completed a third round of strikes this week against Iran, "holding Iranian forces accountable for attacking another commercial ship in the Strait of Hormuz."

Iran retaliated later by targeting US bases and facilities across the Gulf, with Iranian media saying the strikes targeted US military facilities in Kuwait, Bahrain and Qatar.

The General Command of the Bahrain Defense Force (BDF) said on Sunday that its air defense systems intercepted and destroyed several Iranian aerial attacks targeting Bahrain.

In a statement, the BDF said Iran continued what it described as a "systematic hostile approach" through "unlawful" missile and drone attacks targeting civilians in the kingdom.

Iranian authorities: Passage through Hormuz Strait currently not possible

Iran's Persian Gulf Strait Authority (PGSA) announced on Sunday that due to the US military forces' recent "illegal movements" in the region, passage through the waterway is not currently possible.

It made the announcement in a post on social media platform X, saying, "Once stability and calm are restored, all requests (for passage through the Strait of Hormuz) will be reviewed according to the schedule, and the necessary permits will be issued."

The PGSA stressed that the only way to receive permission for crossing the strait is through its website PGSA.ir.

US military says southern Hormuz route open           

However, the US-led Joint Maritime Information Center said on Sunday that despite Iran announcing the closure of the Strait of Hormuz, the southern route along the Omani coast remains available and has been expanded to accommodate two-way traffic.

The advisory, released by the United Kingdom Maritime Trade Operations, cited additional information from the US Naval Forces Central Command (NAVCENT), which said the Strait of Hormuz is an international waterway and is not subject to coercion or control by any single nation.

"Despite Iran's claims that the Strait is closed, US forces are prepared to maintain freedom of navigation and safeguard lawful commerce," NAVCENT said, adding that the southern route through the Strait remains open.

Following the signing of an MoU between the United States and Iran, two alternative transit routes effectively emerged: a northern route controlled by Iran and a southern route along the Omani coast, where US forces provide navigation support and coordination.

UN chief urges maximum restraint 

At the United Nations, UN Secretary-General Antonio Guterres is deeply concerned by the serious escalation and renewed military confrontations in the Gulf, including the Iranian attacks on ships in the Strait of Hormuz, the attacks by the United States on Iran, and the attacks by Iran on targets in the neighboring countries, his spokesperson said on Sunday.

The UN chief "calls on all parties to exercise maximum restraint, avoid further escalatory action and take immediate steps to de-escalate," spokesperson Stephane Dujarric said in a statement.

"These attacks must all stop," the statement said.

Arab countries express concern, condemnation

Egypt on Sunday condemned the Iranian attacks, calling them "a flagrant violation" of the sovereignty of the countries affected, the Egyptian Foreign Ministry said in a statement.

The attacks represent "a dangerous escalation that threatens the security and stability of the Gulf region and undermines efforts aimed at reducing tensions and consolidating regional security," the ministry said.

Egypt stressed that no pretexts or justifications could be accepted for such attacks, calling for an immediate halt to all escalatory actions and adherence to international law to prevent further tension and instability in the region.

The Iraqi Foreign Ministry expressed concern over the continuing tensions and developments affecting maritime security in the region.

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A ministry statement said that these developments could have potential repercussions for regional security and stability, as well as for international trade.

While calling for dialogue and diplomatic means to address differences, the ministry reaffirmed Iraq's support for all efforts aimed at de-escalation, preserving the security and stability of the region, and safeguarding the shared interests of its peoples.

The United Arab Emirates (UAE) also condemned the Iranian missile and drone attacks.

In a statement, the UAE Ministry of Foreign Affairs reaffirmed the UAE's solidarity with the countries targeted and reiterated its support for measures to safeguard their security and stability.

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The UAE Ministry of Defense said on social media that its forces were intercepting incoming missiles and drones, while its National Emergency Crisis and Disasters Management Authority said the situation remained stable, and that missile threats detected earlier were outside the country's borders.

Oman on Sunday summoned Iran's ambassador to deliver a formal note of protest over drone attacks targeting sites in the governorates of Musandam and Al Wusta, Oman's Foreign Ministry said.

In a statement, the ministry said Oman expressed profound dismay over what it described as irresponsible acts, stressing the need to respect state sovereignty, the principles of good neighborliness, non-interference in internal affairs, and the norms governing relations between the two neighboring countries.

Qatar's Foreign Ministry, in a statement, strongly condemned the Iranian attacks targeting its territory and several neighboring countries, describing them as a flagrant violation of sovereignty, territorial integrity and international law.