Justin Trudeau had body armor under his shirt and jacket

Canadian leader Justin Trudeau wore a bulletproof vest and was surrounded by heavy security during an election campaign rally after receiving a security threat, sources told the national broadcaster.

Trudeau had body armor under his shirt and jacket, photos from the event showed, when he appeared an hour and a half late at the 2,000-strong meeting in a suburb of the capital Toronto on Saturday.

He doesn't normally wear a jacket while campaigning.

As Trudeau left the stage to greet supporters he was surrounded by security officers, some with large backpacks on, footage showed.

They were present because of "a security threat", national broadcaster CBC news cited sources from Trudeau's party as saying.

The prime minister's campaign team declined to comment, the outlet said.

His wife, Sophie Gregoire Trudeau, was expected on stage to introduce him but did not appear, local media said.

During the election campaign the Royal Canadian Mounted Police is keeping a daily record of online hate messages aimed at political leaders, fearing possible violent acts, CBC reported.