Some 5,000 were evacuated from Spain’s Canary Islands as lava continued to flow slowly from a volcano, the head of the regional government said Monday.

Lava was flowing on the island of La Palma toward the sea, moving at 700 meters (2,300 feet) per hour, according to the Canary Islands Volcanology Institute.

The lava was moving in two streams through a mostly unpopulated area, Canary Islands government chief Angel Víctor Torres told SER radio. Some 20 isolated houses were destroyed, SER reported.

“We’re not expecting any other eruption,” Torres said, adding that air traffic in the area was not affected.

“There will be considerable material damage,” he said. “We hope there won’t be any personal injuries.”

The eruption opened two fissures, about 200 meters (650 feet) apart. Officials said the lava streams would likely merge before reaching the sea.

The lava crept into the town of Los Llanos de Aridane, which lies close to the volcano. Town Mayor Noelia Garcia said people had been evacuated from houses all the way down to the shoreline.

Experts said the eruption could last for weeks or even months.

People on La Palma largely live from farming.

Spanish Prime Minister Pedro Sanchez was due to visit the affected area Monday after canceling his trip to New York to attend the U.N. General Assembly.

The volcano erupted Sunday after a weeklong buildup of seismic activity that was closely monitored by authorities.

The Canary Islands Volcanology Institute reported the initial eruption shortly after 3 p.m. near the southern end of the island, which saw its last eruption in 1971.

Huge red plumes topped with black-and-white smoke shot out along the Cumbre Vieja volcanic ridge, which scientists had been monitoring following the accumulation of molten lava below the surface and days of small earthquakes.

Most of those evacuated found family or friends to take them in. The rest were in shelters, officials said.

La Palma, with a population of 85,000, is one of eight volcanic islands in Spain’s Canary Islands archipelago off Africa’s western coast. At their nearest point, the islands are 100 kilometers (60 miles) from Morocco.

A 4.2-magnitude quake was recorded before the eruption, which took place in an area known as Cabeza de Vaca on the western slope as the ridge descends to the coast.

As the eruptions continued, at least two open mouths belched bright red magma into the air that then flowed in tight streams down the mountain slope.

Authorities closed seven roads.

Mariano Hernandez, president of La Palma island, asked people to stay away from the eruption.

“People should not come near the eruption site where the lava is flowing,” “We are having serious problems with the evacuation because the roads are jammed with people who are trying to get close enough to see it,” Hernandez said.

Itahiza Dominguez, head of seismology of Spain’s National Geology Institute, told Canary Islands Television that although it was too early to tell how long this eruption would last, prior eruptions on the Canary Islands lasted weeks or even months.

The last eruption on La Palma 50 years ago lasted just over three weeks. The last eruption on all the Canary Islands occurred underwater off the coast of El Hierro island in 2011. It lasted five months.