UK says 'stopped' seven terror attacks in last six months

British security services have foiled around seven terror attacks since June with fighters returning from Syria posing a growing threat, Prime Minister David Cameron said on Monday.

"Our security and intelligence services have stopped something like seven attacks in the last six months, albeit attacks planned on a smaller scale" than Friday's attacks in Paris, he told BBC Radio 4 from Turkey.

Cameron said he still needed to convince more British lawmaker to carry out military strikes against Islamic State (IS) targets in Syria.

The British government, which is already involved in bombing IS targets in Iraq, had lost a parliamentary vote in 2013 to extend military action to Syria.

However, Cameron added that he would take immediate action if UK interests were at stake, citing drone attacks which had killed British militants in August.

Britain is also to recruit an extra 1,900 security and intelligence staff to counter the threat of terrorist violence following the Paris attacks, British media reported on Monday.

It would be the biggest increase in British security spending since the 7 July, 2005 bombings in London that killed dozens of people.