It's clear that our adversaries are rubbing their hands in glee. Al-Qaida is lapping it up. —Iain Lobban, chief of GCHQ

LONDON — Al-Qaida and other British intelligence targets are having a field day with the leaks from former National Security Agency contractor Edward Snowden, U.K. spy chiefs told lawmakers Thursday in a strong condemnation of the American's spying revelations.

Iain Lobban, chief of the eavesdropping agency GCHQ, said his spies have picked up "near-daily discussion" of the unauthorized disclosures among his agency's targets. His colleague John Sawers, the chief of the British foreign spy agency MI6, was even more explicit.

"It's clear that our adversaries are rubbing their hands in glee," he told lawmakers. "Al-Qaida is lapping it up."

Lobban, Sawers and Andrew Parker, head of MI5, Britain's domestic spying agency, were giving their first public, televised testimony to British lawmakers on Parliament's Intelligence and Security Committee. Their appearances came amid a fierce international debate over British and American intelligence tactics — an uproar triggered by Snowden's revelations.

All three spy chiefs insisted their agencies operate within the law, guaranteeing parliamentarians that their work was both legal and proportionate.

"We do not spend our time listening to the telephone calls or reading the emails of the majority," said Lobban.

During a wide-ranging, 90-minute session, the spy chiefs discussed the war in Syria, cyberattacks against the U.K. and the lingering terror threat from Northern Ireland.

Syria got a particular amount of attention, with Parker warning that the civil war there was drawing in a large number of British residents to fight in the service of Islamic extremism. He said his intelligence service had "seen low hundreds of people from this country go to Syria," noting that some of them had since returned to the U.K.

European intelligence officials have long warned that the war between rebels and Syrian President Bashar Assad's government was attracting foreign fighters from European countries, many of whom have joined hard-line Islamic militant groups.