OSLO - Lithuania reopened air traffic at Vilnius airport, its largest and busiest air hub, on Sunday after hours of suspensions and diversions triggered by reports of balloons in its airspace affected thousands of travelers, the airport's operator said.

European aviation has repeatedly been thrown into chaos in recent weeks by drone sightings and air incursions, including at airports in Copenhagen and Munich.

Air traffic at Vilnius was restored at 4:50 am (0150 GMT) on Sunday after a decision was made late on Saturday to close the airspace "due to a possible series of balloons heading toward Vilnius Airport," the operator said in a statement on its Facebook page.

The temporary restrictions affected both arriving and departing flights, with some flights being cancelled, the operator said. In total, around 30 flights and nearly 6,000 passengers were impacted, it added.

Flights diverted to Latvia, Poland

Lithuania's public broadcaster LRT cited the head of the country's National Crisis Management as saying late on Saturday that 13 balloons were heading towards Vilnius airport.

According to notices posted to the US Federal Aviation Administration's website, the flight restrictions were due to "hot air balloon flights."

It was not immediately clear who launched the balloons and what kind they were.

The Vilnius airport said that throughout Sunday, flight delays may occur due to disrupted crew and aircraft rotations. Overnight, most incoming flights redirected to neighboring Latvia and Poland, while departures were cancelled. One flight due to arrive from Copenhagen returned to Denmark.