The United States bugged European Union offices and gained access to EU internal computer networks, the German magazine Der Spiegel reported Saturday, citing NSA documents leaked by Edward Snowden.
Der Spiegel cited from a September 2010 "top secret" National Security Agency document that it said the fugitive former NSA contractor had taken with him to Hong Kong and which its journalists had seen in part, Reuters reported.
The document outlines how the NSA bugged offices and spied on EU internal computer networks in Washington and at the United Nations, not only listening to conversations and phone calls but also gaining access to documents and emails. The document explicitly called the EU a "target."
The revelation is the latest in a cascade of disclosures set off by Snowden's flight.
According to Der Spiegel, the NSA also targeted telecommunications at the Justus Lipsius building in Brussels, home to the European Council that groups EU national governments, by using a remote maintenance unit.
Without citing sources, the magazine reported that more than five years ago security officers at the EU had noticed and traced several missed calls to NSA offices within the NATO compound in Brussels.
Each EU member state has rooms in Justus Lipsius with phone and Internet connections, which ministers can use.
The spying methods resemble those reportedly used by the British at the 2009 G20 Summit in London, which saw the UK's Government Communications Headquarters into phones and computers used by heads of state. That surveillance campaign was uncovered by a separate Snowden leak earlier this month.
Snowden fled from Hawaii to Hong Kong in May, a few weeks before publication in the Guardian and the Washington Post of details he provided about secret U.S. government surveillance of Internet and phone traffic. He has been holed up in a Moscow airport transit area since last weekend.