Canadian Prime Minister Stephen Harper says he is "very concerned" about allegations his country's spies targeted Brazilian officials.

He said Canadian officials are working to repair the damage by reaching out to their Brazilian counterparts.

Mr. Harper did not give details of which Brazilian officials had been approached and added he "could not comment further on national security operations."

Brazilian President Dilma Rousseff said Monday industrial espionage appears to be behind the alleged spying on the country's Mines and Energy Ministry.

Foreign Minister Luiz Alberto Figueiredo summoned the Canadian ambassador to Brazil, to "transmit the indignation of the Brazilian government and demand explanations," the Foreign Ministry said in a statement Monday.

American reporter Glenn Greenwald, based in Rio de Janeiro, broke the story with the aid of former U.S. spy agency contractor Edward Snowden, and the revelations aired late Sunday on Brazil's Globo network.

Canadian companies have large mining interests across the globe, including in Brazil.

Canada is part of an intelligence sharing network that includes the United States, Britain, New Zealand and Australia. Last month President Rousseff canceled a state visit to the United States due to revelations the U.S. National Security Agency spied on her personal communications and those of other Brazilians.

The affair is a potential embarrassment for Prime Minister Harper, who visited Brazil in 2011 and met with President Rousseff in a bid to deepen ties with a regional power that is a trading partner and a competitor.

Bilateral relations have improved from the period around 2001, when the two sides were involved in disputes over
Brazilian beef exports and whether Canada was illegally subsidizing foreign sales of airliners.