JAKARTA, Sept 7 — Volcanic ash conditions around several Indonesian airports showed signs of improvement on Monday, with tests at four airports finding no ash at ground level, including four consecutive negative results at Jakarta’s Soekarno-Hatta International Airport, authorities said.

Transport Minister Dudy Purwagandhi said four consecutive ground-level tests at Soekarno-Hatta had returned negative for volcanic ash, but authorities were holding off reopening Indonesia’s main international gateway until they were satisfied that conditions were safe.

“We have conducted four tests, or paper tests, at Soekarno-Hatta Airport and found the results to be negative. However, we are not immediately reopening it because we want to be absolutely certain,” he said during a briefing with President Prabowo Subianto on Monday.

Dudy said additional caution was necessary because wind directions had shifted during the volcanic ash episode, potentially changing the direction in which ash from Anak Krakatau was dispersed.

He said eight airports affected by Anak Krakatau’s volcanic ash had initially been temporarily closed, with Atung Bungsu Airport in Pagar Alam, South Sumatra, reopened at 9 am on Monday after an assessment found it was no longer affected.

The remaining seven airports, namely Soekarno-Hatta, Halim Perdanakusuma, Radin Inten II, Budiarto Curug, Husein Sastranegara, M. Taufik Kiemas and Pondok Cabe, were kept temporarily closed until 6pm local time on Monday.

As of 9am Monday, the volcanic ash had affected about 2,300 flights and 270,337 passengers since September 5, including flights that were cancelled, delayed or diverted, according to Transport Ministry data.

Of these,1,397 flights involving about 177,579 passengers were affected at airports that had been temporarily closed, while another 922 flights and about 92,758 passengers were affected at other airports due to flight route adjustments.

Meanwhile, Meteorology, Climatology and Geophysics Agency (BMKG) chief Teuku Faisal Fathani said at the same briefing that ground-level ash detection tests came back negative at Halim Perdanakusuma, Husein Sastranegara and Budiarto Curug airports.

“We can see that the volcanic ash at higher levels, reaching up to 50,000 feet, has moved away towards the Indian Ocean, while ash at lower levels, from the surface up to 15,000 feet, remains around the affected areas,” he said.

He said BMKG was continuing to coordinate with the Darwin Volcanic Ash Advisory Centre (VAAC), which covers South-east Asia, Australia and surrounding areas, as authorities assessed conditions for the reopening of affected airports.

He said BMKG had also launched a continuously updated aviation weather website where the public could check which airports were closed, the duration of the closures and subsequent changes in their operational status.

Meanwhile, Dudy said Kertajati, Juanda, Ahmad Yani, Adi Soemarmo and Yogyakarta International airports had been prepared as alternatives, while 10 airports were being readied for 24-hour operations to accommodate diverted flights and accelerate the recovery of flight schedules.

He said airlines were also adjusting operations through alternative airports, with Garuda Indonesia and Lion Air operating services through Kertajati, while Singapore Airlines would deploy larger Airbus A350 aircraft through Juanda and Yogyakarta to accommodate more passengers.

Dudy said passengers whose flights were cancelled were entitled to full refunds, while immigration authorities were providing flexibility for foreign nationals who had exceeded their permitted stay due to the disruption. — Bernama