The Canary Islands Volcanology Institute said this was the first eruption on La Palma in 50 years. The last one occurred in 1971. /CFP

Lava flowed down to the sea, destroying some 20 isolated houses, according to local SER Radio. Local experts said the eruption could last weeks or even months. /CFP

A 4.2-magnitude quake was believed to have triggered the eruption. /CFP