Some Canadians have said they are stuck in Israel amid deadly fighting on Sunday, as airlines canceled flights out of the country and reaching the Canadian embassy was difficult over the weekend.

Kendall and Mary Fullerton, from Toronto, were at the ancient site of Megiddo on Saturday when Hamas militants launched thousands of rockets and sent dozens of fighters to infiltrate the heavily fortified border by air, land, and sea.

The unprecedented attack has been described as the deadliest on Israel in years, as the incursion and counterattack resulted in the deaths of hundreds on both sides and injured thousands more.

Kendall Fullerton told the Canadian Press from Tel Aviv: "For now, the situation is fine, but I think Israel will likely ramp up some offensive operations, and this will likely put pressure on other entities throughout the region." He had been on vacation with family members since late September.

The Israeli government officially declared war on Sunday and gave the green light for "significant military steps" to respond to Hamas as the military sought to crush the fighters still in southern towns and intensified its bombing of Gaza.

The Fullerton family reported that Sunday was mostly quiet in Tel Aviv, but they witnessed fighter jets and smoke from distant Arab towns and heard numerous air raid sirens – leading to spells in the hotel bomb shelter – since the incursion.

After their scheduled return flight home was canceled, they spent Sunday trying to book another flight without success, as most airlines continued to cancel flights. Air Canada stated it had temporarily canceled its flights to and from Tel Aviv as of Sunday and would adjust its plans as the situation evolved.

Mary Fullerton also said they had been trying to reach the Canadian embassy in Tel Aviv since news of the attack broke, but they were directed to hotlines and could not obtain direct information due to the embassy dedicating long hours over the weekend for Thanksgiving.

Global Affairs Canada did not immediately respond to a request for comment, but it advised more than 1,400 Canadians registered in Israel and 492 in the Palestinian territories to limit their movements and shelter in place until it is safe to leave.

Ruby Siegel, 22, from Montreal, in Israel for training, said he felt safe in the Efrat settlement in the West Bank, where he was staying with friends for the Jewish Simchat Torah holiday, but felt frustrated by "the lack of care or assistance from the Canadian government."

Siegel also added that he was in a Jewish temple when the air raid sirens went off, prompting multiple trips to shelters and the cancellation of holiday services.

He said he contacted the emergency hotline designated for Canadians in Israel but was redirected to the Canadian embassy. Siegel said he was told the embassy was closed for Thanksgiving, and there would be no responses to travel information requests and emergencies until after the long weekend.

Global Affairs also said on Saturday that there were no injuries or casualties in Canada but has not provided an update since then. The department urged Canadians traveling to the region to exercise "a high degree of caution" in Israel and to avoid travel to Gaza and the country’s borders with Syria, Egypt, and Lebanon.