Three Mexican banks have been forced to activate contingency measures to foil attempts by hackers to infiltrate the country's real-time payments network.

The alarm was sounded by the Mexican central bank on Friday, reporting that three banks experienced “incidents” when operating the SPEI, Mexico’s interbank electronic transfer system

The bank stressed that no client money was lost as a result of the attack and the system continued to operate as normal.

The banks targeted were moved to an alternative network which would result in delays in transferring cash from the usual 1.9 seconds to hours.

In a statement, Bando de Mexico says: "It is possible that the clients of the [three banks will] experience slowness in the sending of their transactions, as well as in the receipt of resources from other financial institutions (possibly of a few hours) and delays in the queries of the electronic certificates of payment."