Gangs raided multiple police stations for weapons in Haiti"s capital, Port-au-Prince, in deadly attacks over the weekend as violence between armed groups flared, with intense conflict in one southern neighborhood forcing thousands to flee. The gangs have proliferated in the poorest country in the Americas over the past few years during a period of political unrest and growing economic misery. Armed groups increasingly outgun Haiti"s security forces and fight with one another over territory. The United Nations said on Sunday it was "profoundly worried" about the impact of the growing violence on civilians, recalling similar incidents over the past year that forced thousands to flee. Haiti is also facing a surge in COVID-19 cases and is bracing for a referendum at the end of June over a new constitution. Attackers raided six police stations over the weekend, killing three police officers and burning their bodies in one attack, local news outlets reported. In another, a police inspector who refused to hand over weapons was shot to death. The head of the national police, Leon Charles, confirmed two of the attacks and the inspector"s death, telling a news conference on Sunday that authorities were intensifying efforts to combat the gangs. He said police had restored control of a highway leading south from the capital that had been blocked by gang warfare around the troubled neighborhood of Martissant since last Wednesday. The latest flare-up appeared to have killed about 10 people - including civilians - and forced thousands to flee the area as assailants torched homes and businesses, the office of civil protection said in a statement. Videos on social media last week showed bodies along the empty highway that was manned by gunmen. The videos also showed displaced people, including children, taking refuge in a church, in a market square and at a sports center. Fresh produce ran low in Port-au-Prince as trucks carrying supplies from the south were blocked. "The phenomenon of gangsterization is taking on more and more alarming proportions," the office of civil protection said, adding there were conflicts in at least three other neighborhoods of the capital. "The security forces are on their knees."