Volcanic ash from two mountains has forced Indonesia to close six airports across the country, during peak travel for the Eid holiday season.
The Juanda International Airport serving Surabaya, closed yesterday but has since reopened today.
State news agency Antara quoted a Juanda International Airport spokesperson as saying: "It's conditional and there is the possibility that volcanic ash could halt air traffic again."
Four smaller airports were also closed due to the volcanic activity at Mount Raung on the main island of Java.
Volcanic eruption of Mount Gamalama led to the closure of an airport in the eastern island of Ternate.
Most of these airports are expected to remain closed until later today.
Indonesia flag carrier Garuda cancelled more than 48 flights to and from Surabaya; Air Asia took similar steps by cancelling all flights from the Juanda International Airport from 1.20pm to 7.20 pm local time Thursday.
Last week, the Ngurah Rai International Airport on the resort island of Bali was closed due to volcanic activity in Mount Raung.
Travellers were also stranded at Blimbingsari Airport in Banyuwangi, Selaparang Airport in Lombok and Notohadinegoro Airport in Jember.
Airlines are less worried about visibility problems and more concerned with damage likely caused to the aircraft from the volcanic ash, which could turn into molten glass when sucked into plane engines, reported AFP.