The monthly number of people migrating into Tokyo and its vicinity in July was less than the number of those moving out of the area for the first time, as the capital became the center of a novel coronavirus resurgence in the country, government data showed Thursday.

The outflow exceeded the inflow by 1,459 people in the capital and the prefectures of Saitama, Chiba and Kanagawa, marking the first negative net migration since the government began compiling figures including foreign nationals in July 2013.

According to the Internal Affairs and Communications Ministry, the number of people moving into the Tokyo metropolitan region dropped 16.1 percent from a year earlier to 29,103 in July. Those migrating from the area fell 5.7 percent to 30,562.

While a concentration of population has been seen in the capital for years, the ministry noted that it "cannot confirm immediately whether this trend is temporary or not," adding that it would continue to monitor the data in the coming months.

The net population outflow totaled 2,522 in Tokyo alone, which saw a spike in the number of new infections last month. The net outflow more than doubled from 1,069 in May. Kanagawa also reported a net outflow of 679 in July, while Saitama posted a net population inflow of 553 and Chiba 1,189.

In terms of age, a large net population outflow was seen in Tokyo for those aged between 0 and 4 years old and those in their 30s.

Tokyo Gov. Yuriko Koike raised the alert for the pandemic to the highest of four levels in mid-July, signifying that "infections are spreading." Several governors of other prefectures also called on their residents to refrain from traveling to the capital.

Tokyo remains the hardest-hit area, with more than 20,000 cases confirmed. The recent surge is said to reflect increasing infections occurring at nightlife establishments or while people dine out.