The Transport Ministry said four airports – Halim Perdanakusuma Airport in Jakarta, Raden Inten II Airport in Lampung, Budiarto Airport in Curug and Pondok Cabe Airfield – were closed after volcanic ash was detected in the areas, according to the Jakarta Globe newspaper.
Earlier, authorities said Soekarno-Hatta International Airport had been temporarily closed since 1.30 am Sunday (1830GMT Saturday).
Authorities said they continued to monitor the movement of the volcanic ash and were coordinating with airport operators, AirNav Indonesia and the Meteorology, Climatology and Geophysics Agency.
A total of 33 flights were canceled due to the temporary closure of Soekarno-Hatta International Airport alone.
Around 23,000 passengers were affected by the closures, while 170 aircraft that had remained overnight on the apron at Soekarno-Hatta were confirmed safe.
Anak Krakatau, located in the Sunda Strait between Java and Sumatra, has remained at Level III since July 2, the second-highest level in Indonesia's four-tier volcano alert system, with a 3-kilometer (2-mile) exclusion zone around the volcano.
Director of Earthquakes and Tsunamis Wilya Yanto said continuous eruptive activity, including repeated ejections of lava, was still being observed Sunday morning, although the frequency had decreased.