National Security Agency accused of monitoring computers around world

The US National Security Agency has reportedly implanted software in nearly 100,000 computers around the world - but not in the United States - that allows the US to conduct surveillance.

Citing NSA documents, computer experts and US officials, The New York Times said secret technology using radio waves was being used to gain access to computers that other countries have tried to protect from spying or cyberattacks. The software network could also create a digital highway for launching cyberattacks, the newspaper reported.

The newspaper said the technology, used by the agency for several years, relies on radio waves that can be transmitted from tiny circuit boards and USB cards inserted covertly into the computers. The NSA calls the effort an "active defence" and has reportedly used the technology to monitor units of the People's Liberation Army, the Russian military, drug cartels, trade institutions inside the European Union, and US partners against terrorism like Saudi Arabia, India and Pakistan.

Among the most frequent targets has apparently been the PLA, which has been accused of launching regular attacks on American industrial and military targets, often to steal secrets or intellectual property.

When Chinese attackers have placed similar software on computer systems of US companies or government agencies, American officials have protested.

The NSA said the technology had not been used in computers in the US.