Cuba's power grid collapsed again on Sunday, plunging the island into a nationwide blackout — the latest in a series of failures that included three similar outages in July. The collapse followed a weekend of intermittent power cuts, according to reports. The blackout comes amid fuel shortages caused by a US-imposed economic blockade, which has restricted the island's access to oil and left its ageing power infrastructure struggling to function. The cause of the latest failure has not been specified, but the country's electrical system has been under severe strain in recent weeks. There was no immediate word on when power would be fully restored.