(Updates with Communist Party official, foreign minister and US Embassy comment, additional context)
By Dave Sherwood
HAVANA, March 17 (Reuters) - Hundreds in Cuba's second-largest city, Santiago, engaged in a rare public protest on Sunday, according to social media and official reports, prompting Cuban President Miguel Diaz-Canel to call for dialogue in an "atmosphere of tranquility and peace."
Protesters in Santiago took to the streets with chants of "power and food," according to videos posted on social media, as blackouts in places extended for 18 hours or more a day, jeopardizing frozen food and ratcheting up tensions on the island.
Cuba has fallen into a near unprecedented economic crisis since the COVID-19 pandemic, with vast shortages of food, fuel and medicine stoking a record-breaking exodus that has seen upwards of 400,000 people migrate to the United States.
Diaz-Canel confirmed the Santiago protest on social media platform X, formerly known as Twitter, shortly after the rally concluded.
"Several people have expressed their dissatisfaction with the situation of electrical service and food distribution," Diaz-Canel said. "The disposition of the authorities of the Party, the State and the Government is to attend to the complaints of our people, listen, dialogue, explain the numerous efforts that are being carried out to improve the situation, always in an atmosphere of tranquility and peace."
Diaz-Canel also said "terrorists" from the United States were seeking to foment further uprisings.
"This context will be taken advantage of by the enemies of the Revolution, for destabilizing purposes," Diaz-Canel said on X.
Police had arrived in Santiago to "control the situation" and to "prevent violence," according to an account posted on social media by state-run CubaDebate.
It was not immediately clear whether anyone had been arrested during the protest.
Beatriz Johnson, a Santiago Communist Party official, said protesters in the eastern Cuban city had been "respectful" and had listened "attentively" to the government's explanations of food and electricity shortages.
Videos on social media suggest the rally was peaceful.
The Cuban capital, Havana, and outlying neighborhoods surveyed by Reuters appeared calm late into Sunday evening. Reuters could not immediately confirm the veracity of videos on social media of alleged protests in other Cuban cities.
The U.S. embassy in Havana said it was monitoring the protests in Santiago and elsewhere.