The blast tore through the engine room of the tanker MKD Vyom without warning on the morning of 1 March. “There were immense shock waves and a fireball,” says Basis*, a seafarer on one of the first ships to suffer a fatal attack in the Gulf of Oman during the US and Israeli airstrikes against Iran.

“For one or two seconds, I was knocked out,” he says. “Everything went black. The power was gone. I looked up – fire and thick black smoke was pouring down.”

Shocked by the explosion, he tried to make sense of what was happening, before realising he needed to escape – and quickly.

“The engine room had been destroyed. There were metal pipes, insulation covers, tanks, torn apart. A 2cm-thick solid fire door, glass windows – bang, all gone.

“I thought: ‘I’m alive. I have to get out of here.’”

Basis’s extraordinary testimony to the Guardian lays out in detail for the first time the terrifying experiences of the seafarers on the ships at the centre of the US-Israeli war against Iran.

He is “one of the lucky ones”, he says, surviving an incident from which not everyone escaped alive.

The Marshall Islands-flagged tanker MKD Vyom had been bound for Ras Tanura in Saudi Arabia, from Amsterdam via the strait of Hormuz. Amid the escalating conflict, the ship had been instructed to stop, report anything suspicious and await further instructions, Basis says.

More than 100 miles from Iran, “very far” from the strait and with no ships nearby, no one was unduly worried, he says.

At the time Basis had no idea that, two hours before the MKD Vyom was hit, another tanker, the Skylight, had come under attack, killing one seafarer and leaving another missing.

He recalls how, despite almost suffocating from the thick black smoke that burned his throat and lungs, his training and familiarity with the vessel kicked in. In complete darkness, he somehow found the exit and the stairs and dragged himself up to the bridge.

“Twice or three times, I was almost senseless with suffocation. But I thought: ‘If I collapse, I will die.’ God helped me, I believe, because I do not know how I found the courage.”

On deck, an eerie silence engulfed the vessel.

“A running ship is alive, you feel it, there is always noise. But you could have heard a pin drop. It was very calm. The ocean was also calm, no wind.”

It was then he learned that his “beloved colleague” and a “good friend of everybody”, Dixit Solanki , 32, an oiler from Mumbai, India, remained missing, probably in the engine room, where the fire was still raging.

To find him on a vessel with no mains power and a damaged engine, the 21-strong Ukrainian, Indian and Bangladeshi crew had to fight the flames with just fire extinguishers and sand.

Some began lowering buckets over the vessel’s side and into the sea, hauling seawater up by hand, in an increasingly desperate attempt to control the blaze.

It took four hours to extinguish the fire before the rescue operation could begin. But despite their best efforts, it was already too late. Basis and another crew member found their colleague dead, lying under wrecked and twisted metal in the engine room.

“We tried our best to recover his body, for us and for his family,” says Basis. But a second blaze began and the fire began to spread via ruptured oil tanks.

With a cargo of 60,000 tonnes of petrol onboard, the situation had become critical.

“If fire spread and came to the cargo side, we all would be vanished,” he says. Shortly afterwards the captain gave the order to abandon ship.

“Leaving the vessel, leaving a colleague behind, trapped in the engine room, was unbearable,” says Basis. “We used our training and fought the fire. But we felt like we had failed.”

On Thursday, Amratlal Gokal Solanki, 64, said his son Dixit was his “hero”.

The seaman was “calm, hardworking and a gentleman”, always willing to help others, “no matter how tired after long hours at sea”, his father said. “He was not just a sailor – he was a son, a protector and the heart of the family. His loss has left an emptiness that can never truly be filled.”

Solanki, a retired seafarer, said governments and shipping companies must do more to protect ships’ crews travelling through conflict zones: “No sailor should have to fear losing their life simply for doing their job.”

The family of Ashish Kumar, from Bihar, who was the captain of the Skylight, which was hit hours before the Vyom, have not heard from him since before the attack, but refuse to believe he is dead.

Ansu Kumari, his wife, says she cannot accept he is gone. “They go abroad to build a future. If something like this happens, families are destroyed. I have full faith that he is trapped somewhere. He will definitely come back,” she says.

Since the 1 March, 10 seafarers have been killed in the strait of Hormuz and the wider region, in 32 attacks on ships. It is unusual for seafarers, who are often not trade union members and fear being blacklisted by unscrupulous shipowners, to speak out.

After Basis and the crew were rescued by another vessel, the ship’s management company arranged for them to be put up in Oman, where they were given counselling and medical treatment. They were sent home on 4 March.

Ten weeks on from his ordeal, Basis stresses that he is speaking on his own behalf, not for his company nor any other crew member, to highlight the plight of the 20,000 innocent seafarers who remain stranded on about 800 ships in the strait of Hormuz, unable to escape.

Other ships are sitting at anchor in nearby ports. The waterway, which normally carries a fifth of the world’s daily oil and liquid gas supplies, has been virtually shut since the US and Israel first launched strikes on Iran on 28 February.

Safe at home with his family, his thoughts often return to his fellow seafarers in the gulf, who have been left at the mercy of a protracted geopolitical crisis that, despite a ceasefire, shows no sign of being resolved soon.

“My fellow seafarers are suffering,” he says. “They are trapped, worse than prisoners, without communication, with limited food and water.”

Echoing the words of the UN secretary general, António Guterres, who called for the implementation of a coordinated plan to evacuate the seafarers, Basis called for countries to sit down and work out how to best get the trapped mariners home.

“It is now the time for all the member states in the shipping sector to do what they need to do to allow our seafarers to escape the strait of Hormuz,” says Basis. “These are the people who kept the global economy going through the pandemic. They are innocent victims.”

Since the conflict began on 28 February, the International Transport Workers’ Federation (ITF) has seen a tenfold increase in seafarers needing help, from 200 to 2,000 cases.

Mohamed Arrachedi, ITF’s flag of convenience coordinator for the Arab world and Iran, says he has 70 WhatsApp messages requiring immediate attention. Most want repatriation, away from conflict zones, others are seeking unpaid wages, including cases where they have been abandoned by shipowners, and others are reporting shortages of food. They are, he says, in increasing distress.

“When you are speaking to a 45-year-old man with a family and he is in tears, saying ‘my life is in your hands’, but you can’t promise any solution, it is a difficult situation,” Arrachedi says.

“The seafarers are telling the world, our lives are in danger They need protection. All governments must come together and find a solution,” he adds.

V Ships Asia, the MKD Vyom’s management company, says the incident had sadly resulted in the death of a “greatly valued crew member”.

* Name changed at the request of the interviewee

Additional reporting by Sajad Hameed