United Kingdom, April 16 -- A Booking.com data breach has led to concerns about a rise in "reservation hijacks".

The Dutch online travel agency has confirmed to customers that they recently noticed "suspicious activity", and that criminals have gained access to names, email addresses, phone numbers and details about past and present bookings.

But they haven't said how many customers have been affected, and where they are based.

However, Booking.com insisted financial information has not been obtained from their systems.

In an email to customers, which has been seen by the BBC, Booking.com told guests: "We recently noticed suspicious activity affected a number of reservations and we immediately took action to contain the issue."

Booki...