JAKARTA: Indonesia's main airport and several other air travel hubs reopened early Tuesday (Sep 8) after days of closure due to ash from a volcanic eruption, the Transport Ministry said.

The ministry wrote on Instagram that the airport serving the capital Jakarta and four others near the city or around the island of Java are now operating again, as the air safety crisis that left hundreds of thousands of travelers stranded subsides.

Mount Anak Krakatau, about 150km from Jakarta, erupted on Saturday, spewing a fountain of lava and a plume of volcanic ash. 

Eight airports halted operations over the weekend after ash was detected in their airspace, disrupting nearly 3,000 flights and leaving more than 340,000 passengers stranded, the Transport Ministry reported on Monday.

Early Tuesday, the ministry posted on Instagram that Jakarta's airport and four others are up and running again.

Jakarta's main airport wrote on Instagram that "following the current volcanic eruption activity of Mount Anak Krakatau, Soekarno-Hatta International Airport has resumed flight operations". 

Earlier, the airport closures had been repeatedly extended.

Airlines now face the daunting task of getting all the stranded passengers onto planes and to their intended destinations after days of chaos at the airports.

Singapore Airlines had cancelled 18 flights on Monday. Another flight departing Jakarta early Tuesday was also cancelled.

In an update at midnight Tuesday, the advisory on its website showed that six flights on Tuesday morning have been retimed, with departure timings pushed to the afternoon.

The other four airports listed as reopened include Halim Perdanakusuma, a smaller Jakarta-area airport that caters to both civil and military flights, and Hussein Sastranegara in Bandung, the capital of West Java, the Transport Ministry said.

Another small airport in south Sumatra resumed operations on Monday morning. Two of the original eight are still closed.

More than 240 domestic and international flights were cancelled or delayed due to volcanic ash on Monday morning alone, Soekarno-Hatta airport said, adding that nearly 30,000 passengers were affected.

The Transport Ministry had prepared six alternative airports as options for aircraft that were originally scheduled to land in Jakarta.

Anak Krakatau, which means Child of Krakatau, sits in a strait that separates the islands of Java and Sumatra. 

The volcano has been sporadically active since it emerged from the sea at the beginning of last century in the caldera that formed after the 1883 eruption of Mount Krakatau. 

A 2018 tsunami triggered by a collapse of parts of Anak Krakatau killed 429 people and displaced thousands.