The Dutch Minister of the Interior and Kingdom Relations will question the U.S. Embassy over the purpose of its rooftop antennas, the minister wrote in a letter to the House of Representatives Monday.

Minister Ronald Plasterk will question the embassy after concerns were raised that the antennas can be used to intercept data from mobile phones used in the nearby Ministry of the Interior in The Hague and the Binnenhof, where the houses of parliament are located.

The issue was raised by the Dutch radio show “Met het Oog op Morgen” (“With an Eye on Tomorrow”) and led to formal questions in the House on Nov. 18.

While it is technically possible to intercept phone traffic from a nearby building, that does not mean that is actually happening, wrote Plasterk in response to those questions. It is common for embassies to use antennas for their own communication, he added.

Foreign powers are not allowed to conduct intelligence operations on Dutch soil unless they have the necessary approval, said Plasterk. Operations conducted without that permission are “unacceptable,” he said. But there is no reason to currently assume that the U.S. does not comply with the agreements, he added.

Nevertheless, Plasterk said he would ask the embassy for clarification, adding that he would brief the House about the outcome.

The Ministry of the Interior could not immediately respond to a request for comment. The U.S. Embassy could not be reached for comment.

The Dutch action follows a report from the Italian magazine L’Espresso last Friday that claimed that the U.S. National Security Agency has been spying on Italian communications from installations on the roof of the U.S. Embassy in Rome and the consulate in Milan.

In late October, a report in Germany’s Der Spiegel claimed that not only did U.S. intelligence agencies listen in on Chancellor Angela Merkel’s mobile phone conversations, but they also used the U.S. Embassy in Berlin as a listening station. A special unit of the CIA and NSA can monitor a large part of mobile phone conversations in the government quarters from the roof of the embassy, Der Spiegel reported.

Both the Italian and the German spying reports were based on documents provided to reporters by former NSA contractor Edward Snowden.