OTTAWA, Jan. 9 (Xinhua) -- Canada's Transportation Safety Board (TSB) has been invited by Iran's accident investigation agency to the site where a Ukrainian airliner crashed, killing 176 people on board, including at least 63 Canadians, the board said Thursday in a statement.

"We have accepted this invitation and we are making arrangements to travel to the site. The TSB will be working with other groups and organization already on site," the board said.

Iran's Aircraft Accident Investigation Bureau is in charge of the investigation according to international aviation rules. A Ukrainian delegation has been reportedly working on site with the Iranian authorities.

Canadian Prime Minister Justin Trudeau said Thursday his government has intelligence indicating that an Iranian surface-to-air missile shot down the Ukraine International Airlines plane.

However, the Iranian authorities have repeatedly denied allegations or speculation that the crash of the Ukrainian flight was caused by an Iranian missile attack.

Iranian technicians and experts from Boeing will examine data from the black boxes recovered from the crash site to determine the cause of the crash, Mohammad Eslami, Iran's Minister of Road and Urban Development, told reporters Thursday.