People wearing face masks exercise at a reopened fitness club in Barrie, Ontario, Canada, on July 17, 2020. (Photo by Zou Zheng/Xinhua)

Canada's gross domestic product grew 4.5 percent in May because businesses reopened after unprecedented economic lockdowns due to the COVID-19 spread in March and April, according to Statistics Canada on Friday.

May saw rebounds across multiple industries with the easing of COVID-19 restrictions, including retail trade that registered a 16.4 percent surge to mark its largest monthly increase since 1961.

May's gains offset some of the March and April declines, economic activity remained 15 percent below February's pre-pandemic level.

In May, 17 of 20 industrial sectors posted increases.

A restaurant with an advertising poster of reopened indoor service is seen in Barrie, Ontario, Canada, on July 17, 2020. (Photo by Zou Zheng/Xinhua)

Both goods-producing industries rose 8 percent while the services-producing sector was up 3.4 percent.

Preliminary information indicates an approximate 5 percent increase in GDP for June and an approximate 12 percent decline in real GDP in the second quarter of 2020.

Owing to their preliminary nature, these estimates will be revised on Aug. 28 with the release of the official GDP for June and the second quarter.