In his hotel room in Tel Aviv, Canadian Artur Wilczynski has quickly adopted a routine intended to keep him alive: His smartphone flashes an alert that missiles are incoming, and he heads to a sub-basement bomb shelter to wait out the latest attack by Iran, listening for the exploding sky to go quiet again.

Right now, there’s no way back to Canada for the retired public servant, who was visiting Israel from Ottawa as part of an international delegation invited by the country’s foreign ministry to meet with members of the LGBTQ+ community.

He had an airplane ticket home for early Sunday morning but all flights were cancelled, and the airspace closed. Some of his fellow delegates investigated taking a ferry to Cyprus, off the Greek coast. It wasn’t running. Crossing into Sinai and driving across Egypt was rejected as too risky.

“There’s not much we can do to get out,” he said, in an interview with The Globe and Mail on the telephone from his hotel room.

So Mr. Wilczynski is trapped, like many of the roughly 7,400 Canadians who were travelling in Iran, Israel, the West Bank and Gaza when war suddenly broke out between the two countries.

Global Affairs said in a statement Sunday that it has not received any reports of Canadians injured or killed in the escalating tensions. Over the past three days, the government has raised the risk levels for a number of Middle East countries, advising Canadians to avoid all travel to Israel and Iran, to exercise caution when travelling to Qatar, and to avoid non-essential travel to parts of Jordan.

The government continues to urge Canadians to register with Ottawa if they are currently in the Mideast. The latest count from the registry puts nearly 79,000 Canadians in the region, including more than 2,129 in Iran and another 6,376 in Israel, West Bank and Gaza. This is an increase of about 2,000 people since last week, but still not considered a full account, since registration is voluntary.

One of the Canadians trying to get out of Iran is Panid Borhanjoo, who flew there two weeks ago to visit his grandmother. Dr. Borhanjoo, an internal-medicine physician, was scheduled to be back in Hamilton, Ont., on Monday, treating patients at Juravinski Hospital. Instead, last Friday night, waves of Israeli missiles devastated buildings only blocks from where he was staying in Tehran.

Since then, as the two countries have exchanged airstrikes, he has been trying to return to Canada. According to a colleague who has been in sporadic contact with Dr. Borhanjoo since the missile strikes began, he has been driving through the mountains, seeking cover when necessary and looking for any route to leave Iran.

“He’s going to try to privately arrange to cross some border,” Dr. Haroon Yousuf said. “I don’t know which border or how he’s going to do it, because essentially, I think he’s trying to arrange for himself to be smuggled out.”

In Tel Aviv, Mr. Wilczynski’s own career experience as a diplomat in conflict zones tells him that staying put is the safest choice for now. On balance, he said, “sheltering in place, as they’re recommending, is the best option.”

Still, he said, hiding in the bomb shelter has been “quite an experience” for Canadians who aren’t used to it. Members of his delegation have taken comfort from the relatively unflustered reaction of Israeli citizens, well practised in air-raid protocol.

“Different people react to it differently,” Mr. Wilczynski said. “Folks are generally calm, but a lot of that comes from seeing the reaction of Israelis for whom this is something they are used to.”

While the delegation, he said, understood that travelling to Tel Aviv carried risks, they were not prepared for a full-out war between Israel and Iran. Along with their families back home, they are all well aware that they are caught in a unpredictable fight between two countries that can do serious harm to each other.

“It can spiral,” Mr. Wilczynski said. “That is something people are very mindful of.”

He said he has been receiving regular updates from the Canadian embassy, which also advised downloading the same attack-alert app that is now keeping him safe.

In Iran, however, Dr. Borhanjoo has received little direction from Canadian authorities, Dr. Yousuf said.

Madina Meghani, a health care worker in Hamilton, told a similar story as she spent the weekend sending e-mails and making calls, desperate for information on how to help one of her friends, a Canadian teacher from Thornhill, Ont. The teacher was visiting family in Tehran, when hostilities with Israel escalated.

Helping Canadians in Iran is complicated, not only because the country has heavily restricted social-media and internet traffic. There has not been a Canadian embassy in Iran since 2012, when Canada severed diplomatic ties with the country for supporting terrorist regimes and violating human rights. Iranian Canadians seeking assistance in Iran must co-ordinate with the embassy in Turkey, which was closed over the weekend.

Aviation authorities in Iran have also closed the country’s airspace until further notice, according to state media. And the Middle East’s two largest airlines − Emirates and Qatar Airways − have cancelled all flights through Iran without providing a resumption date.

Ms. Meghani said the teacher, whom she declined to name because she wasn’t able to get the person’s permission, is relying on family and friends to advocate for her return to Canada.

Dr. Borhanjoo is getting similar support: A petition started by Dr. Yousuf demanding officials expedite his colleague’s return to Canada has received more than 600 signatures.

“Canadians of all stripes, colours and backgrounds deserve protection when they’re abroad,” Dr. Yousuf said. “This today has happened to an Iranian Canadian, but this can happen to Canadians of origin of different places when they’re visiting their loved ones.”

Mr. Wilczynski, meanwhile, plans to remain in place, awaiting further instructions, ever watchful of his smartphone − which suddenly buzzed toward the end of the interview. The app was urging Mr. Wilczynski to take shelter again.

“I have to get ready. I just got the warning,” he said, realizing he needed to get his shoes on. “Yeah, I gotta run.”