An April report disclosed by a NATO committee that has since been taken down apparently revealed the locations of U.S. nuclear weapons in several European countries.

Canadian Sen. Joseph Day for the Defense and Security Committee of the NATO Parliamentary Assembly authored the document, titled, "A new era for nuclear deterrence? Modernisation, arms control and allied nuclear forces," but accidentally leaked the placement of 150 nuclear weapons across Europe.

An excerpt of the document, published Tuesday by Belgian news outlet De Morgan, noted that “these bombs are stored at six US and European bases — Kleine Brogel in Belgium, Büchel in Germany, Aviano and Ghedi-Torre in Italy, Volkel in The Netherlands, and Incirlik in Turkey.”

However, the report does not cite the information about the locations of the nuclear arsenal. A revised version of the document was published online last week, but the locations were left out.

In an email to the Washington Post, Day stated that all information used in the document was "open source material" and that the leaked April report was a draft of the final version to be handled by the NATO Parliamentary Assembly in November.

An unnamed NATO official told the Washington Post that the report is "not an official NATO document" because it had been written by members of the NATO Parliamentary Assembly.

But other officials expressed indifference toward the revelation.

Kingston Reif, director for disarmament and threat-reduction policy at the Arms Control Association, told the Washington Post in an email there was "no surprise" that U.S. nuclear weapons were being stored in Europe.

"This has long been fairly open knowledge," Reif wrote.

De Morgan also reported that the nuclear arsenal contains B61 nuclear bombs.