The Arab Spring protesters bent on bringing freedom to Tunisia, Egypt and Libya are "the strongest answer" to the fanatics behind the 9/11 attacks a decade ago, the European Union said Friday.

"Ten years on, the people in the streets of Tunis, Cairo, Benghazi and across the Arab world have sent a strong signal for freedom and democracy," said EU president Herman Van Rompuy and European Commission president Jose Manuel Barroso.

"This is the strongest answer to the fatuous hate and blind fanaticism of the 9/11 crimes," they added in a joint statement.

Remembering the victims of the 9/11 and other terrorist attacks, the two EU leaders said Europe remained "shoulder to shoulder with our friends and allies in the global fight against terrorist networks and their economic backbone."

The EU would continue to boost law enforcement cooperation and protect transport systems and critical infrastructure, they said.

The EU was also taking new steps to identify and combat the conditions conducive to the spread of terrorism, they added as the EU's executive arm prepared to launch a grassroots network aimed at spotting potential recruits to extremist causes, from hardline Islamists to far-right lone wolves.