Israel issues evacuation warning to residents of Arak in central Iran

US President Donald Trump is preparing plans to potentially attack Iran in the coming days, Bloomberg cited senior US officials as saying, possibly over the weekend.

The situation was fluid and could change, Bloomberg reported, adding that leaders at some federal agencies were preparing for the possibility of the potential attack.

Iranian authorities arrested 18 people in the northeastern city of Mashhad, Iranian state media reported on Thursday local time, accusing them of designing and manufacturing drones for Israel.

According to a report by Revolutionary Guards-affiliated Fars News, the suspects were allegedly operating under the cover of local workshops as they produced surveillance and suicide drones on Israel's behalf.

The US military has withdrawn some aircraft and ships from Mideast bases due to their vulnerability to a potential Iranian attack, Reuters reported on Wednesday citing two US officials.

Ships had been moved from a Bahrain naval bases and fighter planes which could not be placed in reinforced shelters were relocated from the al-Udeid air force base in Qatar, Reuters cited the sources as saying.

Israel told the Trump administration that while its munitions may not be able to reach deep enough into Iran's Fordow underground nuclear facility, Israel may "do it with humans", Axios reported citing a US official.