The guards' families and trade union criticized the government's response on Thursday.

The wife of one of the abducted guards, who asked to remain anonymous for security reasons, told Reuters she has had no information about her husband's whereabouts for five days.

Prisons agency SNAI said in a statement on Thursday that operations to free the hostages were ongoing. Videos purporting to show prison staff being subjected to extreme violence, including shooting and hanging, have circulated on social media, although armed forces commander Rear Admiral Jaime Vela said on Wednesday (January 11) that no hostage had been killed.