Attacks on tankers sailing through the Strait of Hormuz hit their highest last week of any week since the Iran war began, Reuters reports citing maritime security sources tracking incidents.

Attacks, attempted attacks and harassment activity, including drone overflights, surveillance and hailing using VHF radio by Iran’s Revolutionary Guards have persisted in the strait, the US Navy-led Joint Maritime Information Centre (JMIC) says in a note from Sunday.

“These actions continue to demonstrate Iran’s intent to assert presence along key transit lanes and maintain pressure on transiting vessels,” the JMIC adds.

From September 28 to October 5, there have been at least 12 attacks on oil, liquefied natural gas and liquefied petroleum gas tankers around the Strait of Hormuz, according to data from three maritime security sources who analysed incidents based on information received from the area.

That is the highest number of attacks in a single week since the US war on Iran began on February 28, the sources say.