A sequence of volcanic eruptions at Anak Krakatau and a shallow magnitude-5.5 earthquake struck the Sunda Strait in the early hours of Wednesday, prompting Indonesian authorities to reinforce safety protocols for coastal communities and maritime traffic. No injuries or structural damage had been reported by midday, according to the national disaster-mitigation apparatus.

Gunung Anak Krakatau, located in the narrow seaway between Java and Sumatra, produced at least six distinct eruptive pulses from just after midnight until late morning, the volcanology centre (PVMBG) of the energy ministry reported. Ash columns rose between 100 and 250 metres above the summit, drifting northwest, while seismographs recorded maximum amplitudes of 50 millimetres and eruption durations of up to 44 seconds. The volcano remains at Level III (Siaga), and a 3-kilometre exclusion radius around the active crater is in force. The Indonesian Association of Disaster Experts (IABI) separately urged residents along the coastline to review evacuation routes and protect respiratory health if ashfall reaches settlements.

At 02:44 local time, a tectonic earthquake of magnitude 5.5, later revised from an initial 5.3, occurred 62 kilometres southwest of Sumur in Banten province at a depth of 43 kilometres. The meteorology and geophysics agency (BMKG) classified it as a shallow thrust-fault event linked to subduction of the Indo-Australian plate and confirmed that modelling showed no tsunami potential. Ground shaking was felt with an intensity of IV MMI in Sumur and III MMI in parts of Pandeglang and Bogor, with social-media reports of tremors waking residents as far away as South Tangerang and southern Sumatra. No aftershocks were detected through 03:05, BMKG said.

Elsewhere in the archipelago, Mount Lewotobi Laki-Laki in East Nusa Tenggara and Mount Merapi in Central Java both exhibited heightened activity, remaining at Level III alert with exclusion zones of 5 kilometres and 3 kilometres respectively. Merapi produced a pyroclastic flow that travelled 2 kilometres down the Boyong river channel at midday. The simultaneous unrest across several volcanic systems is not unusual for Indonesia, which sits on the Pacific Ring of Fire, though the clustering has drawn close monitoring from geological agencies. As of Wednesday afternoon, all affected volcanoes remained under continuous observation, and authorities reiterated calls for the public to avoid prohibited zones and to rely only on official information.