Verizon signals returning after a massive outage across the US

Verizon said its wireless services are back online after having suffered an outage that affected many major cities across the US.

Tens of thousands of users had their mobile phones showing no bars or SOS, with the nation's largest wireless carrier offering no reason for the outage.

The company has more than 146 million customers around the country and received at least 33,000 complaints.