According to the tracking site Downdetector, issues were reported with the sites of ANZ, Westpac, St George, ME bank, Macquarie Bank, Allianz, and the Commonwealth Bank.

Early on Thursday, multiple airlines in the US and Australia also suffered outages -- including American Airlines, Southwest Airlines, United Airlines and Delta Air Lines, and Virgin Australia, the BBC reported.

Australian tech commentator Trevor Long suggested that problems with web services company Akamai could be behind the wave of issues.

Akamai provides one of the world's largest content delivery networks (CDNs).

Earlier this month, an internal problem at another large CDN, Fastly, prompted an hour-long outage at several high-profile websites including Amazon, Reddit, and the UK government site.