Global data centers used by Google and Yahoo are among the resources tapped by the National Security Agency (NSA), according to reports.

On Wednesday, The Washington Post published new leaks disclosed by whistleblower Edward Snowden, which detailed how the NSA “has secretly broken into the main communications links that connect Yahoo and Google data centers.”

Under a project, dubbed MUSCULAR, the intelligence agency – working with its British counterpart, GCHQ – is able to collect millions of records from the data centers, sending them daily to NSA’s headquarters in Fort Meade, Md., the paper revealed.

The Post published a sketch obtained from an NSA presentation which shows how the “public internet meets the internal Google cloud” – or how undisclosed access points are intercepted to tap into private data, much of which belongs to Americans.

According the Post, Google claimed that it was not aware of the NSA’s activities, while a Yahoo spokeswoman said the company has “strict controls in place” to secure its data centers and that it had not given the NSA, or any other government agency, access to data centers.