Counter-terrorism officers at UK ports have seized £250,000 in suspected funding for extremists in countries including Syria in the space of a year.

Officers in north-west England intercepted the cash at ports in the region in the last financial year, with 60% to 70% of the total found to be heading for terror groups in so-called "risk areas" including the Middle Eastern state.

Customs officers and airport staff can seize money they believe is being carried out of the UK for terrorist purposes, and police then have 48 hours to investigate.

Around 30% to 40% of the money confiscated was found to be for legitimate purposes, Greater Manchester Police said.

The figure was revealed amid increasing concern about the number of Britons travelling to Syria to join extremist factions including Islamic State, and what will happen if they decide to return home.

Last week counter-terrorism teams from Scotland Yard disrupted a suspected "significant plot" in the UK and arrested and questioned five men.

One line of inquiry is to establish any possible links with Islamic State, the extremist group behind the beheading of British aid workers Alan Henning and David Haines.

On Friday the terror threat level for police officers and staff was raised, with workers warned to "remain vigilant and alert to any possible dangers".

The risks faced by police were underlined last month when terror suspect Abdul Numan Haider was shot dead in Australia after stabbing an officer.

He launched his attack without warning outside a police station in Melbourne after two officers had arranged to meet him about his cancelled passport.