OTTAWA, January 10. /TASS/. A thorough and credible investigation is needed to determine the causes of the crash of the Ukraine International Airlines plane in Tehran, Canadian Prime Minister Justin Trudeau told a press conference on Thursday.

"Canada is working with its allies to ensure that a thorough and credible investigation is conducted to determine the causes of this fatal crash. As I said yesterday, Canadians have questions, and they deserve answers," Trudeau said.

"We have highlighted that it is extremely important that there be a thorough and credible investigation on site of the crash with international partners. The Iranians have indicated that they understand that. With the conclusions that we have been able to draw, or the preliminary conclusions we have been able to draw, based on intelligence and evidence today are clear enough," he added.

"We have intelligence from multiple sources, including our allies and our own intelligence. The evidence indicates that the plane was shot down by an Iranian surface-to-air missile," Trudeau said. "This may well have been unintentional. This new information reinforces the need for a thourough investigation into this matter," he added.

On January 8, the Ukraine International Airlines Boeing 737 plane en route from Tehran to Kiev crashed shortly after takeoff near Tehran Imam Khomeini International Airport. According to Ukrainian Foreign Minister Vadim Pristayko, there were 176 people on board, and no one survived. Among them were citizens of Afghanistan, Germany, Iran, Canada, Ukraine, the United Kingdom and Sweden.