Thousands of Indonesians were spending a miserable Eid Friday after failing to make it home to see their families as erupting volcanoes closed six airports, including in the country's second-biggest city.

The international airport serving Surabaya, the largest city after the capital Jakarta, and four smaller airports were closed on the eve of the Muslim holiday by the eruption of Mount Raung on the main island of Java.

The airport on the remote, eastern island of Ternate was shut due to ash drifting from erupting Mount Gamalama, the transport ministry said.

Weary travellers expecting to join their families for the final night of the Islamic fasting month instead spent the night in packed airport terminals, with many sleeping on the floor.

Surabaya's airport and a smaller one in East Java reopened Friday, the transport ministry said, with some airlines resuming flights in the afternoon.

But there were significant delays, with dozens of flights put back hours.

AirAsia resumed some flights "earlier than scheduled", it said, as ash from Mount Raung began drifting away from Surabaya's airspace, but was forced to cancel and schedule others.

Indonesian flag carrier Garuda also resumed some domestic and international routes, sending two of its larger planes to Surabaya to help clear the backlog.

"Finally flying," wrote Twitter user Jack Putera from Surabaya.

However four terminals -- three on East Java and one in Ternate -- remain shut due to volcanic eruptions, prolonging the travel misery for thousands of passengers.

It is unclear when they will reopen but the transport ministry said the situation was being "reevaluated every hour".

Garuda has cancelled all flight to those airports, stating it would only resume services when those terminals were reopened by the "competent authority".

In recent days, people across the vast archipelago have taken to planes, boats and cars to head to their home towns and villages to celebrate Eid, which marks the end of the fasting month of Ramadan and falls on Friday.

The shutdowns came just days after the airport on the resort island of Bali was closed by ash from Mount Raung, stranding thousands of foreign holidaymakers. Bali airport was open and operating normally Thursday.

Air traffic is regularly disrupted by volcanic eruptions in Indonesia, which is home to 130 active volcanoes.

The main concern for airlines regarding volcanic ash is not that it can affect visibility but rather that it could damage aircraft, as it turns into molten glass when sucked into plane engines, according to experts.

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Garuda

AirAsia