Canada expelled eight Soviet officials last week for spying on scientific, technological and military targets and has in recent months barred nine others from returning to the country, government sources say.

Prime Minister Brian Mulroney said Tuesday that the diplomats and trade representatives were engaged in "improper and unacceptable behavior."The officials were believed to have links to both the KGB and to the GRU, intelligence organizations run by the Soviet military, government sources told the Canadian Press news agency.

Government officials in Ottawa said the eight Soviets expelled last week included two people from the Soviet Embassy and six others who held diplomatic status and were based in Montreal.

The other nine completed their normal tours of duty in Canada and returned home at various times over the last six months or so, the sources said. All have been declared persona non grata, meaning they cannot return to Canada.

The sources said the targets of the expelled Soviets were primarily scientific and technological. One told Canadian Press there were military objectives as well.

Mulroney confirmed the expulsions Tuesday at a final summit news conference when asked about them by a Canadian Broadcasting Corp. reporter.

"I will confirm the government of Canada took some action last week in regard to the improper and unacceptable behavior by representatives of the Soviet government in Canada," he said.