The Raung volcano in Banyuwangi district began erupting on Sunday, spewing ash up to 2,000 metres into the sky, according to the Indonesia's volcanological centre.
There were no reports of casualties.
The Lion Air group said it cancelled six flights to and from Banyuwangi on Monday because of the airport's temporary closure.
"The closure was caused by the eruption of Mount Raung. Volcanic ash can damage the components of an aircraft and endanger flights," said Lion Air spokesman Danang Prihantaro.
Meanwhile, the -19 cases in Indonesia rose by 8,242 within one day to 1,166,079, with the death toll adding by 207 to 31,763, the health ministry said on Monday.
According to the ministry, 13,038 more people were discharged from hospitals, bringing the total number of recovered patients to 963,028.
The virus has spread to all the country's 34 provinces.
Specifically, within the past 24 hours, Jakarta recorded 3,144 new cases, West Java 1,500, Central Java 826, East Java 585 and East Kalimantan 344.
No more new positive cases were found in two provinces, namely West Kalimantan and Gorontalo. - dpa