More than 1,500 prisoners escaped from a Maputo prison Wednesday, taking advantage of the third day of unrest triggered by the controversial confirmation of the long-ruling Frelimo party as the winner of recent elections.

A total of 1,534 detainees escaped the high-security prison located about 15 kilometres (nine miles) from the capital, said national police chief Bernardino Rafael at a press conference. Among those attempting to escape, 33 were killed and 15 wounded in clashes with prison staff, he added. A search operation, backed by the army, led to the arrest of about 150 fugitives, he said.

Around 30 of the prisoners were linked to armed groups that have been behind unrest and attacks in the northern province of Cabo Delgado for the past seven years. “We are particularly concerned about this situation,” Rafael said.

On Wednesday, groups of protesters had approached the penitentiary, creating confusion and triggering unrest inside the prison, where inmates ended up knocking down a wall through which they escaped, he explained.

In addition to stores and public buildings that were already ransacked Monday, ambulances were set ablaze along with a drugstore and other businesses, according to an AFP correspondent. Some demonstrators also set up tables in the streets to occupy the space while celebrating Christmas with family or neighbours, an AFP journalist witnessed in several working-class districts of Maputo. A few residents ventured out to buy food and drink, but many supermarkets had been vandalized. Those that did reopen had shortened hours.

US State Department spokesman Matthew Miller had said there was “a lack of transparency” about the results and urged all parties to “refrain from violence and engage in meaningful collaboration to restore peace and foster unity”. But on Tuesday, the Mozambique interior ministry said that 21 people including two police officers had been killed in 24 hours in street clashes.

Interior Minister Pascoal Ronda also said 236 “acts of serious violence” occurred. “Groups of armed men using bladed weapons and firearms have carried out attacks against police stations, penitentiary establishments, and other infrastructure,” Ronda had said. At least 25 people were wounded, while more 70 people had been arrested, he said.