BRUSSELS -- Commercial flights in the European Union (EU) are showing an upward trend as summer begins, according to data published on Monday by Eurostat, the EU's statistical office.

Along with the tourism industry, the aviation sector has been badly hit by the COVID-19 pandemic, grounding aircraft on the tarmac as containment measures and travel bans were put in place.

During the second wave of outbreaks in early 2021, the number of commercial flights decreased sharply by about 70 percent compared to the pre-pandemic levels in 2019, according to Eurostat.

In June, however, the number of commercial flights went back significantly to only 54 percent less than two years ago, thanks to the vaccination campaign and the ease of lockdowns in the EU.

"Now that it is much easier to travel within the Mediterranean space and in Europe, we see a strong increase in demand," said Benjamin Smith, CEO of Air France-KLM, to French radio Europe 1 last week.

Air France-KLM planes departing from France towards trendy touristic destinations such as Greece, Italy, Spain, and Portugal, are full, said Smith.

As European airlines are on the way to recovery for intra-EU travel, it is another story altogether when it comes to long-haul flights and extra-EU travels. Routes towards Asia and Latin America are still closed, said Smith.

The EU launched a Digital COVID Certificate on July 1, aiming to facilitate travels within the Schengen area and restart the tourism industry. The bloc is currently in talks with the United States and some other countries for mutual recognition of vaccine certificates.