LONDON (Reuters) - British police said on Thursday that they had arrested a man on suspicion of financing terrorism acts linked to overseas conflicts, but that there was no immediate threat to Britons.

Police said officers from the South East Counter Terrorism unit apprehended a 27-year old man in Slough, on the outskirts of London, on suspicion of committing a terrorist offence.

Local Police Area Commander Simon Bowden said the arrest on Thursday morning was pre-planned but not in response to any immediate threat to people in the local area.

Britain raised its international terrorism threat level in August to the second highest classification of "severe", meaning an attack was considered highly likely, and there have been a series of arrests since.

Prime Minister David Cameron and security officials have repeatedly warned of the threat posed by Islamic State (ISIS) militants who have taken over swathes of Syria and Iraq and Bowden cautioned that the whole community needed to help prevent those seeking to travel to war zones.

"I would ask that we all continue to discourage anyone from attempting to travel to Syria or other areas of conflict," he said in a statement.