More than 1,000 refugees fleeing fighting between the army and leftist guerrillas in Colombia have crossed the border into Ecuador in the past few days and a local official warned that the number could rise.
Aid groups say the refugees are scared and hungry, and relief workers are struggling to provide them with food, mattresses and clothing in shelters in the Ecuadoran town of San Lorenzo, 12km from the Colombian border.
"We are handing out light clothing, but we lack cooking gear and we have only about 300 of the 600 mattresses we need," Felipe Basan, disaster relief coordinator for the Ecuadoran Red Cross, said on Saturday.
"We don't know how long they are going to be here and we expect that more people will be arriving," San Lorenzo Mayor Gustavo Samaniego said.
There are currently about 250,000 refugees living in Ecuador, the UN said in a statement.
Most of them are Colombians who have fled an internal armed conflict that has raged there for more than 40 years.
The UN estimates about 3 million Colombians have been driven from their homes by violence without leaving the country -- making it the largest internal refugee population in the world after Sudan.
Vice President Lenin Moreno called on Colombia to resolve the refugee problem.
"It pains us what is happening in our neighboring country, but unfortunately it is not our problem," Moreno said.
"It is a problem that they should resolve," Moreno said.
Francisco Ortiz of the Red Fronteriza de Paz, a group representing border communities in Ecuador, said the recent flight was prompted by fighting between Colombia's army and National Liberation Army guerrillas near their communities.
Ortiz said the refugees arrived on Thursday "in the worst human condition," and that many were scared, hungry and sick.