The U.S. National Security Agency snooped on the Indian embassy and considered it a “target” along with 37 other embassies and missions here, according to the latest revelations by The Guardian, which has steadily been trickling out data obtained by the fugitive whistle-blower Edward Snowden.

This week, the newspaper reported that the NSA used “an extraordinary range of spying methods” against the Indian and other diplomatic posts in the U.S., deploying everything from bugs implanted in electronic communications gear to taps into cables to the collection of transmissions with specialised antennae.

U.S. intelligence bosses, including National Intelligence Director James Clapper, have defended the Obama administration’s mega-scale surveillance of global Internet and telephone communications authorised by the shadowy Foreign Intelligence Surveillance Court as a necessary process for protecting American national security interests.

However, this week, the news that foreign embassies of allied and friendly nations were also put under surveillance here caused outrage, with a spokesman for the German Chancellor, Angela Merkel, warning that “bugging friends is unacceptable.”

While the Indian embassy could not be reached for comment in time for this report, The Guardian exposé on the spying methods used against embassies said a key method was code-named ‘Dropmire,’ which, according to a 2007 document, is “implanted on the Cryptofax.”

This is said to be a reference to a bug placed in a commercially available encrypted fax machine used at missions such as that of the European Union.

It is unclear whether the Indian embassy uses such a device.

According to The Guardian, the NSA documents noted that the machine was used to send cables back to foreign affairs ministries in the home countries.

In addition to India, nations friendly with the U.S. were placed under surveillance, according to the NSA documentation, and these included the EU missions and the French, Italian and Greek embassies, as well as a number of other American allies, including Japan, Mexico, South Korea, and Turkey. “Traditional ideological adversaries and sensitive Middle Eastern countries” were also on the list of targets, the report noted.