A pregnant Canadian mother and her husband were among 16 people killed after a bomb packed with nails detonated inside a bustling tourist café in Morocco on Thursday.

Israeli-Canadian Michal Zekry and Moroccan-born Messod Wizman died after the blast in the city of Marrakech, a close family friend told The Canadian Press.

Zekry, 29, and Wizman, believed to be 31 or 32, moved to China a few months after their marriage so he could pursue a business opportunity, Stephanie Dadoun said, adding that their deaths have left family and friends in shock.

"It's hard for me to put into words everything that she was," she said.

3-year-old left with grandparents

The couple were visiting Wizman's parents in Casablanca and left their three-year-old son with them when they headed to Marrakech for a day trip.

The Moroccan government did not release names but said that two Canadians, two French citizens, a Dutchman and two Moroccans were among the dead. As well, more than 20 people were wounded.

Canada's Department of Foreign Affairs said Friday it only had confirmation of one Canadian death.

Moroccan authorities said the explosive device was packed with nails when it was set off remotely just before noon local time on Thursday, blowing the facade off the two-storey café, which is popular with tourists.

'Big plume of smoke'

"There was a big detonation, a very big detonation, which made us stay still and lower our heads. We saw a very big plume of smoke, and a lot of objects go up in the air," Stéphane Le Pretre, a 46-year-old French tourist, told The Associated Press.

Morocco's Interior Minister Taieb Cherqaoui took issue with an earlier report from Interpol that said the attack was a suspected suicide bombing.

"This was not a suicide attack," Cherqaoui told a meeting of government commission in Rabat, adding that the bomb contained aluminum nitrate, among other components.

The Argana café where the attack happened is on the Djemma el-Fna square, a UNESCO World Heritage site.

With files from The Canadian Press