Trenggalek, Central Java. Authorities in Indonesia are intensifying efforts to clamp down on the dangerous practice of launching giant, homemade hot air balloons during the festive Eid season, after 19 such balloons were detected interfering with commercial flight paths—some soaring as high as 30,000 feet.

AirNav Indonesia, the country’s air traffic control agency, confirmed the incidents occurred during this year’s Eid holidays, prompting safety warnings to local communities who continue the traditional balloon launches despite strict regulations. The agency's president director, Captain Avirianto Sutarno, raised the alarm during a visit to a regulated balloon festival in Wonosobo, Central Java, on Sunday.

"Some of the 19 balloons reached altitudes of up to 30,000 feet, intruding into aircraft airspace,” Avirianto said. While no accidents were reported, he warned that unauthorized balloon flights posed serious risks to commercial aviation.

The illegal balloon launches have historically spiked during Eid celebrations, when communities in Central and East Java commemorate the holiday with homemade hot air balloons. The practice is deeply rooted in local culture but increasingly under scrutiny due to the potential hazards to both air safety and public infrastructure.

Although the number of balloon sightings this year is down significantly from 50 in 2024, authorities remain concerned. The latest incidents were reported across multiple areas in Central and East Java, including Pekalongan and Trenggalek.

Law enforcement is taking action. Police in Trenggalek, East Java, have arrested seven suspects following the explosion of a firecracker-laden hot air balloon that caused damage to a house. The blast occurred on Monday--a week after Eid-- damaging the roof, cracking walls, and destroying two washing machines, with estimated losses reaching Rp 15 million ($900). Among the seven suspects, four are minors and three are adults. They were arrested at their homes in Pogalan District after police identified the balloon involved in the incident.

According to investigators, the suspects purchased explosive materials online, assembled the firecrackers, and attached them to a hot air balloon launched during the Eid celebrations. The suspects now face multiple charges under Indonesia’s Emergency Law No. 12/1951, aviation regulations, and Article 406 of the Criminal Code, which carries a maximum sentence of 20 years in prison. "They admitted to building and launching the balloon during the Eid festivities,” said Trenggalek Police Criminal Investigation Chief Eko Widianto on Tuesday.

Elsewhere in Jombang, East Java, police in Jogoroto district, in cooperation with state utility company PLN, confiscated six large balloons during coordinated raids. Some balloons measured up to 10 meters tall. Police warned that in addition to endangering air traffic, these airborne objects could fall on homes or damage power lines.

“Residents admitted they planned to launch the balloons to celebrate Eid. But these balloons, filled with fire and flammable materials, are a serious hazard,” said Jogoroto Police Chief Djulan.

AirNav Indonesia reiterated its support for traditional cultural practices but urged communities to follow safety protocols, including tethering balloons with ropes to prevent them from drifting into regulated airspace.

“Let’s preserve tradition in a way that doesn’t endanger lives or disrupt our skies,” Avirianto said.