Most of the deserting soldiers slipped into Colombia in the same area as the main border crossing blocked by Venezuela's military, Migration Colombia said.

The migration service's director Christian Kruger said the personnel were fleeing Maduro's "dictatorship" and the "pressure" exerted by the armed civilian militias known as colectivos.

He said some had come armed and wearing uniforms, while others arrived in civilian clothes or with their families.

Kruger did not reveal the ranks of the deserters, but it is believed that none of them are from the military's upper echelons.

AFP has seen at least 20 deserters arriving in the border town of Cucuta since Saturday, although none of them were armed or of a high rank.

Kruger said authorities would evaluate the backgrounds of those who have entered -- if they pose no threat, they will be allowed to stay.

Venezuela's opposition leader Juan Guaido, recognized as interim president by 50 countries, has offered amnesty to members of the armed forces who abandon Maduro.

Guaido needs to win over the military's top brass if his bid to drive out Maduro and set up new presidential elections is to succeed.

The military high command has thus far remained loyal to the ruling regime, which scored something of a tactical victory at the weekend when the armed forces prevented Guaido from bringing in desperately needed humanitarian aid stockpiled in Cucuta.

Humanitarian aid, mostly donated by the United States, has become a centerpiece in the power struggle between Maduro and Guaido.

Maduro refuses to allow it in, claiming it would be a pretext to a US invasion.

Venezuela's armed forces number about 365,000 members, There are also about 1.6 million civilians in the "colectivos."