BERN (Deutsche Presse-Agentur -- Use of two flu vaccines made by Novartis AG has been stopped in several European countries over concerns that the products could be unsafe, the pharmaceutical licensing agency Swissmedic confirmed Thursday in Bern.

Switzerland, Italy and Austria have stopped shipments of the vaccines sold under the brand names Agrippal and Fluad.

"First investigations have shown that the Italian ban was mandated after white particles were found in the syringes," Swissmedic said in a statement, adding that the particles could simply be clots of the vaccine.

"Novartis confirms that these particles can occur in the vaccine manufacturing process and is confident that there is no impact on the safety or efficacy of the vaccine," the Swiss-based company said.

On Thursday, Novartis also released its third-quarter results.

Net profit stayed flat year-on-year at 2.48 billion dollars, while sales fell due to the expiry of a patent on a blood pressure medication in the United States.

Copyright 2012 dpa Deutsche Presse-Agentur GmbH