Intensifying volcanic explosions on the Spanish island of La Palma have forced firefighters to retreat and authorities to evacuate three more towns, while airlines cancelled flights because of a cloud of gas and ash, the biggest since the volcano erupted. Firefighters pulled out of cleanup work in the town of Todoque on Friday afternoon as a new vent opened up in the flank of the volcano. Videos shared on social media showed a massive shockwave emanating from the eruption site. A witness saw a huge grey cloud billowing from the top of the volcano on Friday afternoon, the largest since the eruption began on Sunday. “The volcano is in a newly explosive phase ... Firefighters will not operate anymore today,” tweeted the Tenerife fire service, which has been deployed to help on La Palma. Authorities ordered the evacuation of people in the towns of Tajuya, Tacande de Abajo and the part of Tacande de Arriba and residents were told to assemble at the local football ground. Canary Islands emergency services had initially told residents to stay indoors to avoid the dense cloud of ash and lava fragments but later decided to evacuate them due to the heightened risk from explosions. It was not just people being evacuated but animals too. “The evacuation of people is the main priority ... although there are also other important tasks such as keeping pets safe,” the Guardia Civil tweeted, with a video showing officers carrying reluctant goats to safety. Since erupting on Sunday, the Cumbre Vieja volcano has spewed thousands of tons of lava, destroyed hundreds of houses and forced the evacuation of thousands of people. No serious injuries or fatalities have been reported but about 15% of the island’s economically crucial banana crop could be at risk, jeopardising thousands of jobs. The Canary Island airline Binter cancelled all flights to La Palma because of the volcanic eruption, while Iberia cancelled its only flight scheduled for the day, and another local airline, Canaryfly, also suspended operations. Binter said it was forced to halt operations to and from La Palma as the ash cloud had worsened considerably in the last few hours. The airline, which had initially only cancelled night flights, could not say when it would resume operations. A cloud of toxic gas and ash was ascending more than2.5 miles (4km) into the sky, the Canaries volcanology institute said. It was drifting north-east towards the Mediterranean and Spanish mainland, the national weather agency said. Airspace above the island remains open apart from two small areas near the eruption site.