An eruption of Indonesia's Mount Anak Krakatau ​caused the suspension of hundreds of flights at Jakarta's main airport on ‌Sunday after some school activities and fishing were halted.

Soekarno-Hatta International Airport posted on Instagram that it had suspended flight operations until 9:30 a.m. (0230 GMT) due to volcanic ash.

The suspension, extending a halt ​that had been scheduled until 5:30 a.m., has affected 209 flights, including ​several international flights, Indonesia's transportation ministry said.

Anak Krakatau has erupted since late ⁠on Friday, with volcanic ash detected at the airport early on Sunday, the ​ministry said in a statement.

Ash was identified as high as 20,000 feet (6,000 metres) on the ​Java side of the volcano and a plume of up to 50,000 feet (15,000 metres) on the Sumatra side and some parts of Banten province in Java, the meteorological agency BMKG posted on ​its website.

Anak Krakatau is roughly halfway between Java and Sumatra in Indonesia's vast island ​chain, which sits on the Pacific "Ring of Fire", where earthquakes and volcanic eruptions are frequent.

Indonesia's disaster ‌mitigation ⁠agency, BNPB, "urges the public to remain calm while increasing vigilance. In the event of ashfall, people are advised to wear masks and eye protection, reduce outdoor activities, cover water sources and exercise caution when driving, as volcanic ash can reduce visibility," said spokesperson ​Berton Panjaitan.

Several schools ​cancelled activities on Saturday ⁠with students and residents suffering eye irritation from the ash, while fishermen cancelled their fishing trips due to the eruption, local ​media outlet Kompas reported.

The disaster mitigation agency said on Saturday ​there was ⁠no imminent risk of tsunami from the volcano.

 - Reuters