CATIA LA MAR, Venezuela — Victims of the powerful twin earthquakes that jolted Venezuela last month as well as people spared by the destruction on Thursday flooded relief services offered by nongovernmental organizations in the hardest-hit areas.

The demand for help comes as the United Nations launched an appeal for roughly $300 million to assist 1.3 million people in urgent need of aid in the South American country where nongovernmental organizations until recently were targets of government repression. Mobile kitchens and clinics as well as field hospitals now dot public spaces in the northern state of La Guaira, where most of the devastation occurred.

“It is clear at displacement sites that, particularly after two weeks, that people are turning up because they haven’t been able to get their other treatments,” U.N. relief chief Tom Fletcher told The Associated Press during his visit to Venezuela. “So, they’re not turning up with just the fractures now, they’re turning up with those longer-term health needs. And it’s vital that we’re there for them.”

Doctors treating people in that state’s Catia La Mar community on Thursday reported an increase in skin conditions and diarrheal diseases, as well as of requests for medications for the treatment of chronic illnesses, including diabetes and high blood pressure. The emerging diseases can be tied to crowded living spaces and poor water and sanitation conditions, which in many communities predate the earthquakes.

Irma Echarri showed up at a mobile unit on a sidewalk across the street from a church with the boxes of the eyedrops and pain reliever she usually takes, hoping that doctors there could give her new ones. She also wanted to be seen for the pain she developed in her nose after the June 24 earthquakes.

“It hurts a lot,” Echarri, 67, said while waiting to be seen. “It hurts because it hurts.”

Echarri’s home was not damaged, but many of her neighbors are living in temporary shelters or outdoors after 190 buildings collapsed and 856 others were damaged, according to Venezuelan officials, in the back-to-back earthquakes that killed 3,811 people.

The government of acting President Delcy Rodríguez has estimated that the earthquakes left about 18,000 people without a home. The displaced are now living in schools, sidewalks, parks, plazas and other public spaces.

Fletcher, the head of the U.N. Office for the Coordination of Humanitarian Affairs, told AP the United States has so far provided most of the earthquake-response aid. Much of the assistance on the ground is being delivered by local groups that have partnered with global humanitarian organizations.

Among the displaced is Zulbey Reyes, who went to the clinic ran by the Venezuela-based organization Paluz in partnership with the global relief agency International Rescue Committee. Reyes, who was also robbed by the earthquakes of her job as a nanny, sought treatment for the onset of chest pain.

“I thought it was my heart that was sick,” Reyes, 41, said after being diagnosed and receiving medication. “But it’s a nerve that became inflamed after the screams that day.”

The United Nations Office for Disaster Risk Reduction has estimated direct physical damage to housing and infrastructure around $37 billion.

The widespread presence of nongovernmental organizations in the country and the freedom with which the government contrasts with the repression and persecution to which they were subjected in recent years. While Rodriguez served as vice president to former President Nicolás Maduro, organizations were repeatedly accused of anti-government activities and the U.N. local human rights office expelled.

“When you have a crisis of this magnitude, people put the politics to one side and are able to focus on saving as many lives as possible, and that’s what I’m seeing so far in this response,” Fletcher said.