The first sign that a Malaysia Airlines Boeing 777 may have crashed came Saturday, when two large oil slicks were spotted close to where the aircraft went missing earlier in the day.

Among the 239 people on board the plane were two Canadians, who have since been identified as Xiaomo Bai, 37, and Muktesh Mukherjee, 42, according to the flight manifest posted online.

The two Canadians were married and lived with their kids in Beijing, where Mukherjee had been working for the energy company Xcoal Energy & Resources, the company’s CEO Ernie Thrasher said in an email to The Canadian Press.

An airline spokesperson said company officials have not been able to contact their families, but have communicated with the Canadian embassy in Malaysia.

Vietnamese Air Force planes spotted the oil slicks, each between 10 and 15 kilometres long, off the southern tip of Vietnam.

While the Vietnamese government did not confirm that the slicks were related to the missing plane, it said they were consistent with the kinds that would be left by a crashed jetliner.

The air force planes were part of a wider search operation that was launched after Flight MH370 lost contact less than an hour after it departed from Kuala Lumpur at 12:41 a.m. local time on Saturday. The Beijing-bound flight was scheduled to land approximately six hours later.

Malaysian and Vietnamese officials said the plane was last detected on radar at 1:30 a.m. local time, near where the South China Sea meets the Gulf of Thailand.

In a statement Saturday, Malaysia Airlines said 24 hours after the loss of contact, search and rescue teams are “still unable to detect the whereabouts of the missing aircraft.”

A Malaysia Airlines’ senior management team met with family members of the passengers in Beijing and Kuala Lumpur, the airline said.

Two-thirds of the passengers were Chinese nationals, but there were also people from Malaysia, Indonesia, Taiwan, Australia, India, Russia, Europe and North America.

Meanwhile, officials in Italy and Austria said the names of the two nationals listed on the flight manifest as coming from those countries matched names on passports that had been reported stolen in Thailand.

An Italian man named Luigi Maraldi was listed as being a passenger on the flight, but was not aboard the plane, the country's foreign ministry said. Maraldi had reported his passport stolen in Thailand last August.

The foreign ministry in Austria also confirmed that a name of an Austrian national on the manifest matched that of an Austrian passport reported stolen two years ago in Thailand. The ministry would not confirm the identity of the individual, but said the Austrian was not on the plane.

Malaysia Airlines CEO Ahmad Jauhari Yahya said Saturday there was no indication that the pilots of the plane had sent a distress signal, indicating that whatever took place may have happened quickly.

The pilot had more than 18,000 flying hours and had been flying with the airline since 1981, Malaysian Airlines said. The plane's first officer had about 2,800 hours of flying experience and had worked for the airline since 2007.

When asked by reporters about the possibility of a terror attack, Malaysian Prime Minister Najib Razak said it was too early to make any conclusions. But he said the government was looking at "all possibilities."

Family, friends wait for news at Beijing hotel

Meanwhile family and friends waiting for news of their loved ones were overcome with emotion in Beijing.

Beijing airport officials posted a notice asking them to wait at a nearby hotel for more information. Scenes from the hotel showed some of them weeping as they feared the worst.

CTV's Asia Bureau Chief Janis Mackey Frayer said many of them were frustrated with the speed at which information was being relayed to them.

"It was hours before officials at Beijing's airport were directing relatives to a nearby hotel to sit and await news," she reported Saturday from Beijing. "There's really a lot of frustration – fury really – among the families that are waiting.

"There are a lot of anxious relatives, and they've been saying that up to this point – more than 12 hours after the plane was supposed to arrive -- they've received little to no information from Malaysian officials."

In a statement issued late Friday night, Canada’s Department of Foreign Affairs, Trade and Development said they had received preliminary reports indicating that two Canadian citizens may have been “affected” by the missing plane.

“Our thoughts and deepest sympathies are with those affected by the disappearance of Malaysia Airlines MH370,” the statement said. “We are working with local authorities to gather more information on the situation.”

Prime Minister Stephen Harper also expressed his condolences Friday night in a tweet.

With files from The Associated Press and The Canadian Press