Bulgarians had flocked to branches of First Investment Bank (>> First Investment Bank AD Sofia) on Friday and withdrew 800 million levs (327.45 million pounds) after a run had shut down another big lender. The central bank said criminals had tried to disrupt the financial system.

"According to data which the Bulgarian National Bank has, the tensions that arose on Friday as a result of an organised criminal attack on some Bulgarian banks were overcome as of the end of the business day," the central bank said in a statement.

Bulgaria's banking crisis had eased on Monday, with fewer depositors queuing to withdraw savings, after politicians assured them that their cash was safe and the European Commission gave Sofia the green light to provide state aid to its lenders.

"As a result of the measures taken, the banking sector in Bulgaria operates normally," the central bank said.

(Reporting by Tsvetelia Tsolova; writing by Matthias Williams; Editing by Larry King)