TEHRAN (AFP) — Tehran said Sunday it carried out a third day of retaliatory strikes against United States attacks on Iranian territory, as both accused the other of violating their fragile ceasefire, straining negotiations meant to end the Middle East war.

The exchanges underscored the fragility of a Pakistan-brokered peace process aimed at ending a war launched by the US and Israel in February, which disrupted shipping through the Strait of Hormuz and rattled global energy markets.

Iran's Revolutionary Guards said on Sunday they were taking measures to control traffic in the vital Strait of Hormuz and that violating vessels would be dealt with more firmly than before.

The only authorized passage by Tehran passes through a corridor running along Iran's coast.

The Guards said they had also carried out retaliatory strikes in Kuwait and Bahrain.

In a statement, they said the strikes "destroyed eight important US military facilities at the Ali al-Salem base in Kuwait and at the Fifth Fleet naval base in Port Salman in Bahrain."

"Any enemy aggression, whatever the pretext, even against insignificant targets... will have a crushing response," the Guards said.

Air raid sirens rang out twice in Bahrain on Sunday, according to the Gulf nation's interior ministry.

A memorandum of understanding was reached in mid-June under Pakistan's mediation, aimed at putting a lasting end to the war.

The text signed by the US and Iran said both countries, and their respective allies, were "not to initiate any war or any military operation against each other and to refrain from the threat or use of force against each other."

Iran would 'no longer exist'

President Donald Trump said Saturday that Iran would "no longer exist" if the US is "forced" to resume the war.

The threat came after US forces said they struck "multiple" Iranian targets Saturday in another tit-for-tat response to attacks on shipping in the Strait of Hormuz.

"United States aircraft just struck Iranian missile and drone storage locations, and coastal radar sites, for violating the Cease Fire Agreement, AGAIN!" Trump wrote on Truth Social.

"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. If that happens, the Islamic Republic of Iran will no longer exist!" Trump wrote.

US Central Command said Saturday's strikes were in response to an Iranian drone attack on the Panama-flagged oil tanker "Kiku," which was carrying some two million barrels of crude.

The US military said its operation targeted "surveillance infrastructure, communication systems, air defense sites, drone storage facilities, and minelayer capabilities."

Iranian media reported several explosions in the Sirik and Qeshm areas of southern Iran.

Washington had carried out similar strikes on Friday, saying they were a response to an earlier Iranian attack on another vessel, the "Ever Lovely."