Iran has launched attacks on Bahrain and Kuwait after the United States struck five Iranian targets, escalating tensions and threatening the fragile ceasefire agreed by the two sides earlier this month.

The Islamic Revolutionary Guard Corps (IRGC) confirmed the attacks on Sunday, saying it launched ballistic missiles and drones at the US Ali Al Salem airbase in Kuwait and the US Fifth Naval Fleet at Port Salman in Bahrain.

Bahrain condemned the attacks, saying they violated its sovereignty and undermined “opportunities for de-escalation and stability in the region”, while Kuwait described the “repeated heinous Iranian aggressions” as a “flagrant violation of its sovereignty”.

The US military hit Iran’s Sirik, Bandar-e Lengeh and Qeshm Island on Saturday. US Central Command (CENTCOM) said its navy and air force “conducted strikes tonight on 10 Iranian military targets at multiple locations in and near the Strait of Hormuz”, saying the attacks were a response to an Iranian drone attack on the Kiku oil tanker.

It said the Panama-flagged vessel was carrying more than two million barrels of crude oil when it was attacked as it transited near the strait early on Saturday.

Britain’s UKMTO maritime security agency ⁠said the tanker hit on Saturday had sustained damage to its bridge, with all crew reported safe.

Strait of Hormuz

The weekend attacks come after the US struck Iran on Friday following drone attacks on vessels near the Strait of Hormuz.

The Singapore-registered Ever Lovely container ship was hit by a drone on Thursday. No injuries were reported. The US responded by hitting locations near Sirik, while Iran responded by attacking US military locations in the region.

Iran has said vessels transiting the strait can only use its designated route and warned that ships using any other routes would be violating the ceasefire agreement.

The International Maritime Organization suspended its plan to evacuate ships stranded in the strait on Thursday after the attack on the Ever Lovely.

President Donald Trump said late on Saturday that Tehran had violated the ceasefire agreement, which was signed on June 17.

“There may come a point when we are no longer able to be reasonable, and will be forced to militarily complete the job that we very successfully started,” he posted on social media. “If that happens, the Islamic Republic of Iran will no longer exist!”

Iran’s Ministry of Foreign Affairs condemned the US strikes on its monitoring and surveillance facilities on its southern coast. It said the “brutal attacks” were in violation of the Memorandum of Understanding (MoU) and the United Nations charter.

It added that they showed the US “does not place the slightest value and credibility on its commitments” and said Iran would defend its sovereignty and territorial integrity against “US military aggression”.

Speaking in Iraq on Sunday, Iranian Foreign Minister Abbas Araghchi said that “the Strait of Hormuz remains under the total oversight and management of Iran throughout the 30 coming days, and after all obstacles are removed, the total capacity of the waterway will be restored.”

“Any new developments will result in exacerbating the situation, and also delaying the opening of the strait. It will also raise the levels of escalation,” he added, warning that no other party should interfere. He called for all parties to honour their obligations under the MoU, otherwise it will derailed.”

Agreement under strain

The MoU signed by the US and Iran extended a ceasefire in their war that began with US-Israeli attacks on Iran on February 28, giving both sides 60 days to negotiate an end to the fighting.

Access through the Strait of Hormuz is a key element of the MoU. During the war, Iran blocked the waterway through which about 20 percent of the world’s oil passes, triggering a global energy crisis.

Article 5 of the MoU states that Iran will “make arrangements using its best efforts for the safe passage of commercial vessels” through the strait during the 60 days. It states that Iran and Oman, along with other Gulf states, will discuss the future administration of the strait.

Wolfgang Pusztai, a defence analyst, told Al Jazeera that while neither the US nor Iran have an interest in a bigger escalation, “there is a risk that this might happen unintentionally.”

“If there are some hits in residential areas, if a larger number of civilians are getting killed in the Arab Gulf states, if an American base is hit severely so that the American soldiers are killed, this might easily get out of control,” he said.