LISBON, Portugal — Portuguese authorities have confirmed suspicions that the new delta variant of the coronavirus is driving a spike in new cases in the Lisbon region.

Portugal’s National Health Institute said Sunday that the highly infectious variant that was first found in India has a prevalence of 60% of new cases in the nation’s capital.

The recent surge in infections caused authorities last week to ban all travel in and out of Lisbon on the weekends. The measure went into effect on Friday. The Lisbon metropolitan area has around 2.8 million inhabitants.