The Toronto Zoo says a panda on loan from China has given birth to two cubs.

The zoo said the cubs were born early Tuesday, weighing 115 grams and just under 188 grams.

Zoo staff say the cubs and their mother, Er Shun, "all appear to be doing well," but note the next few days and weeks are critical and all three will be monitored around the clock.

It's the first time giant pandas have been born in Canada. The cubs, if they survive, they will live at the zoo for about two years and will likely return to China once they are weaned.

Er Shun and another panda, Da Mao, arrived in 2013 and are slated to move to the Calgary Zoo in 2018.