A tanker in the Strait of Hormuz reported being struck by an unknown projectile, forcing its crew to abandon ship and board a lifeboat, the United Kingdom Maritime Trade Operations agency said on Tuesday as vessel crossings dropped further.

“The optimist may see the latest American attacks as a last attempt to strengthen the negotiating position before a compromise is reached and the Strait of Hormuz is reopened,” an SEB Research note said.

“However, the risk is a more prolonged stalemate, with continued uncertain energy flows, higher oil prices and recurring attacks.”

Limiting price gains, a senior Iranian official told Reuters that Tehran had received a proposal from mediators for a 10-day ceasefire in efforts to salvage the deal signed on 17 June, intended to pave the way for a lasting agreement to end the war that began on 28 February with US-Israeli attacks on Iran.

Yemen’s Iran-aligned Houthis said on Monday that they would impose a naval blockade on Saudi Arabia, opening a potential new front against the US and raising the threat to global energy supplies and trade beyond the Gulf.

“The threats of a naval blockade on Saudi Arabia by the Houthis are significant because they raise the risk of disruption to another major oil exporter,” said Tim Waterer at KCM Trade.

Meanwhile, US crude oil and gasoline stockpiles were expected to have fallen last week while distillate stocks are likely to have risen, a preliminary Reuters poll showed on Monday.