More details have emerged about the U.S. and British spy agencies’ efforts to surveil targets in Germany — including chancellor Angela Merkel.

According to documents leaked by former National Security Agency contractor Edward Snowden, the British spy agency GCHQ conducted surveillance by tapping the servers of three German companies offering super-high-speed wireless Internet service to remote areas. The revelations appeared in German magazine Spiegel yesterday.

The three companies — Stellar, Cetel, and IABG — “provide communications links to places like oil drilling platforms, diamond mines, refugee camps and foreign outposts of multinational corporations and international organizations,” and are connected on the back end to high-bandwidth European Internet backbones.

In other words, those servers are especially choice hubs for monitoring traffic to and from areas of interest to the NSA and GCHQ.

In addition to monitoring the traffic flowing through these servers, the agencies also targeted the companies’ engineers for surveillance, and sought to find out more about their customers and technology suppliers.

Among other high-level international targets, the latest documents confirm that Merkel was a target of the agencies’ spying. Der Spiegel revealed earlier, in October 2013, that the NSA had tapped Merkel’s cellphone and had used the American embassy in Berlin as a listening post.

Other world leaders named as intelligence targets in the NSA documents, as reported by Spiegel, include the prime ministers or presidents of Peru, Somalia, Guatemala, Colombia, Malawi, Belarus, Malaysia, Syria, and Ukraine.