Fiji police are investigating the cause for the two fires in Levuka in the early hours of Sunday.
The fire began after midnight and burned the Westpac bank office, a supermarket and an Air Fiji office.
The Westpac manager in Fiji, David Evans, says the ATM which was just installed six months ago was also destroyed.
But Mr Evans says basic banking service have not been lost.
"In fact, the other bank, colonial bank are kindly assisting us by allowing our staff to be located there from today and so we can speak to customers and establish basic banking services. What we are doing is we are looking for an alternative site to reestablish our Westpac branch in Levuka."