Indonesian and East Timorese civilians are guarding a neutral buffer zone between both countries a day after a land conflict sparked a clash there, a local official said on Wednesday.

The clash erupted on Tuesday evening after a group of East Timorese residents tried to clear land for an immigration office they wanted to build in the zone, Indonesian news portal Tempo.co reported.

The zone, which belongs to neither country, is an area bordering East Nusa Tenggara that is several meters wide and supposed to be free from buildings.

A group of Indonesian residents from nearby Haumeni Ana village in Northern Central Timor district, East Nusa Tenggara, resisted the land clearing, and both groups started throwing stones at each other, Tempo reported. No one was injured but an East Timor security post was damaged, the news portal added.

Lodovikus Lake, head of Bikomi Nilulat subdistrict, which includes Haumeni Ana, said the East Timorese had violated the zone by insisting on building the immigration office, even though the Indonesian Armed Forces (TNI) had earlier told them to stop.

"They keep doing activities in the free zone, upsetting the [Haumeni Ana] residents, who then tried to send them away," Lodovikus said in Kupang, East Nusa Tenggara, on Wednesday.

He added that the situation was returning to normal on Wednesday but residents of both countries were still standing guard around the zone.