Kremlin threats to NATO countries over Ukraine potentially using western-made missiles to hit military targets in Russia would likely take the form of increased sabotage, cyber and other hybrid attacks, said US and European officials.

Russia could also retaliate by directly or indirectly targeting US troops in other areas like the Middle East, another person said.

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Russia has expelled six UK diplomats over spying accusations, the country’s FSB security service said on Friday, ahead of talks between UK prime minister Sir Keir Starmer and US President Joe Biden on the war in Ukraine.

The FSB claimed it had documents showing that the UK Foreign Office department responsible for eastern Europe and central Asia was involved in the “co-ordination of escalation of international military-political situation” aimed at the “strategic defeat” of Russia.

The accreditation of the diplomats whose actions showed “signs of reconnaissance and subversive work” is to be revoked, the FSB said.

The expelled diplomats include British Embassy staff members Jessica Davenport, Grace Elvin, Andrew Daft Callum, Catherine MacDonald, Thomas John Hickson and Blake Pattel, the Russia-24 state-owned TV channel reported. The FSB has not yet confirmed their identities.

The UK Foreign Office did not immediately comment on the Russian move, whose timing will be seen in London as a diplomatic warning shot by President Vladimir Putin.

Starmer will meet Biden in Washington later on Friday to discuss western support for Ukraine in its war against Russia.

Top of the agenda will be whether to allow Ukraine to use western-made weapons for strikes deep inside Russia, after Putin warned that such a move could unleash a war with Nato. Britain has supported the use of such weapons but their use requires US approval.

Ukrainian President Volodymyr Zelenskyy has been lobbying western allies for permission to use the Army Tactical Missile System and Storm Shadow cruise missiles on targets inside Russia.

The UK has long taken a more permissive approach to how the weapons it supplies are deployed by Ukraine.

Less than a week after becoming UK prime minister in July, Starmer said the arsenal of weapons contributed by the UK must be “used in accordance with international humanitarian law” and for “defensive purposes”, but added: “It is for Ukraine to decide how to deploy it for those defensive purposes.” 

A month earlier Rishi Sunak, then UK prime minister, said: “How Ukraine uses the weapons that we provide is for them. Our job is to make sure we give them the capabilities that we can that they need.”

Britain was the first country to send long-range cruise missiles to Ukraine. 

BALTIMORE — Investigators working to pinpoint the cause of Baltimore’s Francis Scott Key Bridge collapse discovered a loose cable that could have caused electrical issues on the Dali, the massive cargo ship that lost power and disastrously veered off course before striking the bridge.

When disconnected, the problematic cable triggered an electrical blackout on the ship similar to what happened as it approached the bridge on March 26, according to new documents released Wednesday by the National Transportation Safety Board.

The documents don’t include any analysis or conclusions, which will be released later in the board’s final report. A spokesperson for the board declined to comment as the investigation is ongoing.

The Dali was leaving Baltimore bound for Sri Lanka when its steering failed because of the power loss. It crashed into one of the bridge’s supporting columns, destroying the 1.6-mile span and killing six members of a roadwork crew.

Safety investigators released a preliminary report earlier this year that documented a series of power issues on the ship before and after its departure from Baltimore. But the new records offer more details about how its electrical system may have failed in the critical moments leading up to the deadly disaster.

The Dali first experienced a power outage when it was still docked in Baltimore. That was after a crew member mistakenly closed an exhaust damper while conducting maintenance, causing one of the ship’s diesel engines to stall, according to the earlier report. Crew members then made changes to the ship’s electrical configuration, switching from one transformer and breaker system — which had been in use for several months — to a second that was active upon its departure.

That second transformer and breaker system is where investigators found the loose cable, according to investigative reports.

Investigators also removed an electrical component from the same system for additional testing, according to a supplemental report released in June. They removed what is called a terminal block, which is used to connect electrical wires.

Engineers from Hyundai, the manufacturer of the ship’s electrical system, said the loose cable could create an open circuit and cause a breaker to open, according to a 41-page report detailing tests completed on the Dali in the weeks after the collapse. The engineers disconnected the cable as part of a simulation, which resulted in a blackout on the ship.

Hyundai sent engineers from its headquarters in South Korea to help with the investigation in April.

The new documents also included various certificates issued after inspections of the Dali pertaining to its general condition and compliance with maritime safety regulations.

“It’s pretty clear that they think they’ve found an issue that could cause a blackout,” said Tom Roth-Roffy, a former National Transportation Safety Board investigator who focused on maritime investigations. He said the loose cable was in a critical place within the electrical system.

He also noted that investigators have clearly taken a thorough approach and documented their findings well. The new documents suggest they found very few other problems as they combed through the various systems and machinery aboard the Dali.

In terms of whether the loose connection suggests inadequate maintenance of the ship or other problems with the crew, Roth-Roffy said it seems like a toss-up. Checking hundreds or thousands of wires is a tedious and time-consuming process, he said, and there are any number of factors that could cause connections to loosen over time, including the constant vibrations on a ship.

“To say that this should have been detected is probably true but somewhat unrealistic,” he said. “But the ship’s crew has ultimate responsibility for the proper maintenance and operation of the ship.”

The Dali left Baltimore for Virginia in late June. It was scheduled to undergo repairs there, and local media reported last week that it will sail to China, likely sometime later this month.