Updated

Two Canadians, including a diplomat, are among at least 39 people killed Saturday during a deadly attack at an upscale shopping mall in Kenya, Prime Minister Stephen Harper said.

An estimated 150 people were also wounded in the attack claimed by Somalia's Al-Qaeda-linked Shebab militants at the packed Westgate mall, popular with wealthy Kenyans and expatriates and part Israeli-owned.

The rebels said the carnage was in direct retaliation for Kenya's military intervention in Somalia, where African Union troops are battling the Islamists.

"Canada condemns in the strongest possible terms this cowardly, hateful act that apparently targeted innocent civilians who were simply out shopping," Harper said in a statement.

He said Annemarie Desloges, a liaison officer with the Canada Border Services Agency at Canada's High Commission to Kenya, would be "remembered and honored."

"Terrorist attacks like this seek to undermine the very values and way of life that Canadians cherish, and they reinforce the need for us to continue taking strong actions to protect the safety of Canadians no matter where they are in the world," he added.

"Acts of terror cannot be allowed to go unpunished."

The Canadian leader said staff at his country's mission were offering assistance to the Kenyan authorities to help bring the perpetrators to justice.

Americans are believed to be among the injured and the wife of a foreign national working for the US Agency for International Development was killed, US Secretary of State John Kerry said.

Paris said two French citizens were among those killed in the attack and Britain warned that some of its citizens were "undoubtedly" among the victims.