London, Sep 1 (IANS) British Prime Minister David Cameron plans to counter threats posed by Islamic State (IS) militants and may consider banning Britain-born jihadis stationed in Iraq and Syria from returning home.

According to officials Monday, British nationals suspected of being involved in terror acts would be allowed to keep their British citizenship but would be prevented from re-entering the country for an unknown period of time, BBC reported.

At least 500 people from Britain are thought to have gone to fight in Syria, although the exact number is not yet known, the officials added.

The number of people arrested in Britain for Syria-related activities stands at 69, according to a recent briefing by senior police officers.

Cameron is also expected to announce plans to make it easier to seize the passports of would-be terrorists travelling abroad.

Britain's terror threat level was raised to "severe" from "substantial" Friday in response to the deepening conflict in Iraq and Syria.