London, Sept 11 (ZEENEWS.COM) In an effort to clamp down on financial links of terrorists, bank accounts of more than 5,000 people suspected to have links with terrorists are being monitored in the UK with 200 of them frozen.

This figure is the security services' highest estimate yet for the number of British-based individuals suspected of involvement in plotting attacks, 'The Observer' reported today.

Quoting senior banking sources, the report said "200 current accounts have recently been frozen as part of the fight against the financing of 'jihadist' terrorism."

The big four banks - Barclays, HSBC, Lloyds TSB and Royal Bank of Scotland which owns Natwest - have been instructed by MI5, the British intelligence agency and the US treasury's office of foreign assets control to monitor "suspicious" transactions involving named individuals and companies.

Sources at Britain's biggest bank, HSBC, said that "just north" of 5,000 UK accounts had been "flagged up" and were being watched as part of evidence-gathering against suspects.

The report claimed that financial details provided by banks played a key part in last month's arrests involving a terror plot to blow up transatlantic airliners and the more recent arrests linked to an alleged network of terror training camps.

Banks have been told to monitor 'cross-border payments' amid evidence that British-based cells are affiliated to terrorist groups such as al-Qaeda.

A senior banking source said: "Every cross-border payment passes through an electronic system. The cross-border stuff we are particularly interested in."

Each of the big four banks has frozen the accounts of around 50 individuals who are suspects, according to the source. The sums involved, however, are generally modest, with most terrorists fearing that moving large amounts through current accounts can attract suspicion.

The banks' action has come for criticism from some British Muslims amid claims of mistaken identities and the persecution of innocent account-holders.

Citing an instance, the newspaper said Ahmed Salama was stunned when his HSBC account was frozen nine days ago. He received a letter informing him that HSBC wished to end their relationship after 11 years.

The decision left Salama unable to pay 12 bills and his mortgage. Despite repeatedly asking for an explanation, HSBC only told him it detected 'suspicious' payments in his account.

Salama, a businessman authorised by the financial services authority whose account was upgraded by the bank only two months ago, said: "The whole situation has put my whole life in a spin, emotionally and financially.

"I am a normal Londoner who plays snooker once a week, a little football and cares for the wife and kids. They have taken everything away from me with no real explanation and have not allowed me to pay bills."

Salama said the only cross-border payment he is aware of making is 20 pounds a month to a British-based charity, which sponsors children in Afghanistan. "My only conclusion is that, with the majority of people being arrested over alleged terrorism offences, having the name of 'Ahmed', they think I am one of them or I am laundering money. I can honestly say I am neither."

HSBC admitted that cases of mistaken identity do sometimes occur.