Israel's defense minister on Thursday said Israel may soon have to "act again" against Iran, to ensure the Islamic republic "does not once again become a threat to Israel."

The UK's terrorism threat level was raised Thursday to "severe", the second highest in the five-tier system, following an antisemitic terror attack the previous day in London, the interior ministry said.

The Israeli army said Thursday that a soldier was killed in southern Lebanon, the fourth such death since a fragile ceasefire took effect there earlier this month.

Dozens of residents and local officials from southern Lebanon gathered in Beirut on Thursday to protest Israel's destruction of their villages, which has been ongoing despite a fragile ceasefire.

Israeli strikes on south Lebanon killed nine people including two children, the health ministry said Thursday, shortly after the president decried ongoing Israeli violations of a nearly two-week ceasefire.

Iran's President Masoud Pezeshkian on Thursday said a U.S. naval blockade of Iranian ports would deepen disruptions in the Gulf and fail to achieve its objectives.

President Joseph Aoun on Thursday decried what he described as Israel's continued violations of the ceasefire, calling for international pressure on Israel to stop strikes on civilians and paramedics.

Aoun slammed the "continuing Israeli violations" in south Lebanon, saying they were occurring "despite the ceasefire, as do demolitions of homes and places of worship, while the number of killed and wounded rises day after day".

Israel's foreign ministry said Thursday that Israeli forces had arrested about 175 activists aboard 20 ships from an aid-laden flotilla bound for Gaza.

"Approximately 175 activists from more than 20 boats... are now making their way peacefully to Israel," the ministry said in a statement, including a video of the activists aboard an Israeli navy ship.

President Donald Trump said a U.S. naval blockade against Iran could last months, leading oil prices to spike to their highest level in more than four years, which held into Thursday.

Trump is expected to receive a briefing on Thursday on new plans for potential military action in Iran from Admiral Brad Cooper, the head of U.S. Central Command, two sources with knowledge told Axios.

Israel's military chief Lieutenant General Eyal Zamir vowed to strike Hezbollah targets north of Lebanon's Litani River and beyond the so-called "Yellow Line" during a visit to south Lebanon on Wednesday.

"Any threat, anywhere, against our communities or our forces -- including beyond the Yellow Line and north of the Litani -- will be eliminated," Zamir said, according to a military statement issued after his visit to troops stationed within a newly-established Israeli security zone in southern Lebanon.