Yemeni authorities have deployed security forces and armored vehicles across the port city of Aden, in preparation for the latest in a series of protests over hours-long electricity outages caused by a shortage of fuel for power stations.

Yemeni authorities deployed security forces and armored vehicles across the port city of Aden Wednesday, as protesters were expected to take to the streets in the latest in a series of protests over hours-long electricity outages caused by a shortage of fuel for power stations.

For several days, hundreds of demonstrators in three central districts of Aden blocked roads and set tires on fire, protesting electricity shortages as temperatures soared to 40 degrees Celsius (104 degrees Fahrenheit).

On Monday and Tuesday, security forces moved in to disperse the demonstrations, beating protesters with batons and barricading the entrances of some streets, three witnesses told The Associated Press on Wednesday.

In recent weeks, electricity outages reached up to 10 hours a day in Aden or up to 20 hours in neighboring Abyan province, according to residents. However, outages lasted only eight hours on Wednesday. The cause of the outages is a shortage of diesel fuel for power stations, the spokesman for Aden’s electricity corporation, Nawar Akbar, said in a Facebook post Sunday.

The impoverished nation has oil fields in the south, a major source of income, but has limited refining capacity and so must import refined fuel.

The government in the south pays up to $1 billion a year to seven private companies to import fuel, but is behind on payments.

A commercial fuel tanker was expected at the port of Aden, but the importer refuses to unload the cargo before receiving payment in advance, the official said, speaking on condition of anonymity because of the internal disputes.

Akbar, of the electricity corporation, said authorities had gotten fuel to one of Aden's power stations Sunday morning and that there were plans to bring in 800 tons of diesel for other stations Monday. There was no subsequent official confirmation whether that had taken place.

Aden has always faced power outages, but those used to only last between four to five hours a day, according to residents. The electricity shortage was cited by Human Rights Watch in a November report highlighting the failure by the Yemeni government and the STC to provide Aden residents with basic rights to water and electricity.

They “have an obligation to provide access to adequate water and electricity in Aden,” said Niku Jafarnia, Yemen and Bahrain researcher at Human Rights Watch. “And yet, when residents have protested the cuts, security forces have responded by firing on them.”