HAVANA — Cuba's Ministry of Energy and Mines said Saturday a total disconnection of the National Electric System took place, the second nationwide blackout reported in a week, according to a statement posted on social media Saturday.

The ministry says protocols to restore electricity service across the country were being implemented.

Meanwqhile, earlier some 650 delegates from 33 countries and 120 organizations have started arriving in Cuba as part of a solidarity caravan transporting some 20 tons of humanitarian aid as the island grapples with a severe energy crisis.

Members of “Our America Convoy to Cuba” arrived Friday by air from Italy, France, Spain, the United States and several Latin American countries. More were scheduled to arrive by sea on Saturday in a flotilla of three vessels from Mexico, organizers reported.

A group of activists arrived in Havana on Wednesday in advance and delivered donations to hospitals. Cuba has been brought to a near standstill since U.S. President Donald imposed an energy embargo in January, exacerbating an economic crisis.