Chris Brown abruptly cancelled his Tuesday-night concert in Montreal, and another show in Toronto, after being turned away at the Canada-U.S. border.

The 25-year-old R&B star said on Twitter he was denied entry at the border just hours before he was to take to the stage in Montreal.

"The good people of the Canadian government wouldn't allow me entry. I'll be back this summer and will hopefully see all my Canadian fans!" Brown tweeted on Tuesday afternoon.

Brown was to perform at the Bell Centre tonight and at Toronto's Air Canada Centre on Wednesday night. He said in his tweets that both shows were sold out.

Nicole Perna, a spokeswoman for Brown, confirmed Canadian immigration officials denied him entry. Perna said Brown can apply to return at a later date and plans to do so. Live Nation, the promoter, said in a statement that "due to immigration issues" the shows have been cancelled and refunds are available at the point of purchase.

A heavy police presence kept watch outside the Bell Centre on Tuesday night.

One group of dejected fans told CBC News they had travelled from New York to see the show.

Another group had called and checked at noon to make sure the concert was still on. They were told it was, and said they left school early to make the trip from Blainville, a Montreal suburb.

Jailed in 2014

Brown was jailed for nearly three months last year for violating his probation by getting into an altercation outside a Washington hotel the previous year. He was on probation after he attacked pop singer Rihanna, his then girlfriend, before the 2009 Grammy Awards. He was also arrested for felony assault in Washington, D.C., in 2013.

In 2010, the United Kingdom denied Brown entry into the country, forcing him to miss four shows. The British government's Home Office said then that Brown had been refused a visa because of his past criminal record.

Stéphane Malépart, a spokesman for Canada Border Services, said the Privacy Act prevents him from commenting on any individual case, but said several factors are used in determining admissibility, including involvement in criminal activity.