EU commissioner says she has assurances that only those suspected of links to terrorism or cybercrime were targeted

Europe pressed the US for greater detail on the Prism surveillance scandal on Friday for the first time and was told that data collection on Europeans was not conducted in "bulk" but only in cases of strong suspicion of individual or group involvement in terrorism, cybercrime or nuclear proliferation.

At a meeting of US and EU justice and law enforcement officials in Dublin, Viviane Reding, the EU commissioner for justice, said she was satisfied that US collection of metadata via the Verizon mobile phone network was "mainly an American question".

The much bigger issues, raised by Edward Snowden's leaks to the Guardian, concerned the NSA hoovering up data from social media and internet servers across Europe in flagrant breach of EU data protection regulations.

Reding said the US and the EU had agreed to set up a working group of security experts to grapple with the implications for the European public.

"Considering Prism, the US answers to the questions I have raised were the following: it is about foreign intelligence threats. Prism is targeted at non-US citizens under investigation on suspicion of terrorism and cybercrimes. So it is not about bulk data mining, but specific individuals or targeted groups. It is on the basis of a court order, of an American court, and of congressional oversight," said Reding.

She emphasised that although national security considerations were vital, the rights of citizens were "non-negotiable'' and also dwelt on the point of the availability of legal redress. Under EU laws, anyone living in Europe, including Americans, can resort to the courts on the grounds that their data privacy rights have been violated. Europeans living in the US cannot go to the US courts in parallel cases.

"I have been asking since a long time already and I continue to ask for full, equal treatment of EU and US citizens. Not more, not less," said Reding.

Eric Holder, the US attorney general, said the Prism programme was aimed at "facilitating the acquisition of foreign intelligence information on targets outside the US". He said the programme was only used if it was "reasonably believed" that the "foreign target" was outside the US and was suspected of being involved in terrorism, cybercrime or nuclear proliferation. Use of the surveillance programme was subject to "extensive oversight".

"Everything is done consistent with the law," Holder said.

Amid outrage across Europe at the vast scale of the US surveillance operations, the US attorney general added that both sides of the Atlantic were engaged in policies aimed at "how to remain vigilant protecting civil liberties".

Under EU data protection rules tabled 18 months ago but not yet agreed among EU governments, crucial passages have been dropped under strong EU pressure making it easier for the Americans to access data on people in Europe.

Reding's spokeswoman said on Thursday that when drafting the rules, the European commission had been faced with "intense US lobbying". A contentious passage in the original draft set stiff conditions for the transfer of data to third countries. This part was dropped.

The new rules are supposed to be agreed by the end of the year. But it is likely that they will now have to be reviewed because of the Snowden leaks and the global impact.