Kanlaon Volcano spewed lava and a five-kilometre ash plume into the sky, sparking evacuations and flight cancellations in the Philippines on Monday night.

The volcano, which straddles the provinces of Negros Occidental and Negros Oriental, belched volcanic gas and material from its summit vent at 6:51 pm on June 3.

State seismological agency PHIVOLCS said in a bulletin: 'The eruption produced a voluminous and incandescent plume that rapidly rose to 5,000 meters above the vent and probable short pyroclastic density currents or PDCs approximately 2-3 kilometers down the southern and southeastern slopes based on IP and thermal camera monitors.

'The eruption lasted six (6) minutes based on the seismic record and was preceded by a relatively strong volcano-tectonic earthquake. Reports of coarse ashfall and sulfurous odors have been reported in communities on western slopes of the volcano.'

Canlaon City Mayor Chubasco Cardenas has ordered the mandatory evacuation of residents living within three metres from the river downstream of the volcano.

He said: 'The rivers downstream from the volcano are at risk of flash floods, mudflows, and other hazards due to volcanic ash deposition and potential lahars.'

Several airlines have also announced flight cancellations due to the eruption.

PHIVOLCS said it is raising Kanlaon Volcano's Alert Level from 1 to 2, indicating increasing unrest. The agency warned that 'shallow magmatic processes that could eventually lead to further explosive eruptions.'

Kanlaon Volcano last erupted in December 2017.

The Philippines is an archipelago of more than 7,000 islands inside the Pacific 'Ring of Fire' where the majority of Earth's volcano eruptions and earthquakes happen.