The Guardian reports: Within hours of news breaking that the US had filed charges against Snowden, the South China Morning Post reported that the whistleblower had handed over a series of documents to the paper detailing how the US had targeted Chinese phone companies as part of a widespread attempt to get its hands on a mass of data.

Text messaging is the most popular form of communication in mainland China where more than 900bn SMS messages were exchanged in 2012.Snowden reportedly told the paper: “The NSA does all kinds of things like hack Chinese cellphone companies to steal all of your SMS data.”

The paper said Snowden had also passed on information detailing NSA attacks on China’s prestigious Tsinghua University, the hub of a major digital network from which data on millions of Chinese citizens could be harvested.

As Snowden made his latest disclosures, the US issued an extradition request to Hong Kong and piled pressure on the territory to respond swiftly. “If Hong Kong doesn’t act soon, it will complicate our bilateral relations and raise questions about Hong Kong’s commitment to the rule of law,” a senior Obama administration official said.

Snowden appeared to be gaining support from politicians in Hong Kong who said China should support him against any extradition application from the US, which on Friday charged him under its Espionage Act. One legislator, Leung Kwok-hung, said Beijing should issue instructions to protect Snowden from extradition before his case was dragged through the courts. Leung urged the Hong Kong people to “take to the streets to protect Snowden”. Another politician, Cyd Ho, vice-chairwoman of the pro-democracy Labour party, said China “should now make its stance clear to the Hong Kong SAR [Special Administrative Region] government” before the case goes before a court.