London, Sep 10 (IANS): A record number of terror arrests were made in Britain last year, surpassing the previous peak, official figures showed on Thursday.

There were 299 arrests for terrorism-related offences in the year to March 2015 -- a rise of 31 percent compared with the previous year and the highest number since data collection began in September 2001, Home Office data revealed.

Some 106 arrests were carried out between October and December 2014, The Guardian reported.

The increase came after the official threat level was raised in August from substantial to severe, meaning an attack is highly likely.

The threat level was heightened as hundreds of so-called foreign fighters were being lured to Iraq and Syria to fight with Islamic State.

Police and security services now believe at least 700 potential extremists from Britain have travelled to Syria.

The previous high of 284 arrests was recorded in March 2006, covering the London bomb attacks in 2005, in which 52 civilians were killed and more than 700 were injured.