Millions of Venezuelans were hit by a new blackout on Monday, the second to hit the OPEC nation this month, that shuttered businesses, plunged the main airport into darkness and left commuters stranded in the capital.

Power went out in much of Caracas and nearly a dozen states in the early afternoon, stirring memories of a week-long outage earlier in the month that was the most severe in the country’s history.

Service was restored in many areas within hours on Monday and Information Minister Jorge Rodriguez said in a televised broadcast that power was being “progressively reestablished.”

Authorities have blamed an “attack” on its electric system for the blackout.

The blackouts come as the country is experiencing a deep political crisis after National Assembly President Juan Guaido invoked the Constitution to assume the interim presidency in January, arguing that Maduro’s May 2018 re-election was illegitimate.

Guaido has been recognised as Venezuela’s rightful leader by most Western countries, including the United States.

Maduro, a socialist who took office in 2013 and who has the support of Russia and China, says Guaido is a US puppet attempting to lead a coup against him.

While blackouts have long been common in Venezuela, their increasing frequency and severity is adding to the desperation of Venezuelans, already living through hyperinflation and six straight years of economic contraction.