The consumer banking website of JPMorgan Chase & Co was temporarily unavailable for a time on Tuesday as the company tried to deal with a denial-of-service cyber attack that slowed access for some customers, a company spokesman said.

The company continued to work late Tuesday to restore normal service, said spokesman Michael Fusco, who declined to say how long the Chase.com site had been down during the day.

Major U.S. banks, including JPMorgan, have recently warned their investors that they are grappling with an increasing number of attacks on their sites that make it hard for customers to conduct transactions.

(Reporting by David Henry; Editing by Edwina Gibbs)