Twenty schools in the affected volcano La Palma have been suspended until further notice and other facilities are in danger.
Schools include educational centers in El Paso, Los Llanos de Aridane and Tazacorte.
The lava also destroyed the Los Campitos school, which has 23 students, and threatens the Todoque school, which has 25 places.
Some 5,500 people were evacuated from risk areas on the island and dozens of homes were destroyed by rivers of molten rock.
Although lava was expected to reach the coast on the evening of September 20, it has yet to do so and scientists warn it could occur today.
When that happens, explosions, poisonous gases and acid rain are expected to engulf the area.
The Spanish Merchant Navy has temporarily banned shipping in areas near the volcanic eruption of La Palma.
“This measure is adopted preventively, because of the inherent risk for navigation, due to the possible arrival of volcanic flows in the sea,” said the government.
The navigation ban affects a limited area of the west coast of the island, to the south by Punta del Pozo (Puerto Naos, Los Llanos de Aridane) and to the north by Playa de las Viñas (Tazacorte) and parallel to the coast, half a nautical mile from said coastline.
It is recommended that maritime navigation in the affected area be conducted along or west of the 017 ° 57.0 W meridian.