By Paulo Prada and Peter Murphy

Caracas (Reuters) - Brazil said on Friday it is pressing Venezuela to determine whether Brazilian gold miners crossed the border and massacred a village of about 80 indigenous people from a helicopter.

The alleged assault, which a tribal group says could have killed more than 70 people in early July, came to light earlier this week when the group asked Venezuela's government to investigate. Because of the remoteness of the region and the scattered nature of the native settlements, fellow tribe members were able to alert the government only on Monday.

Brazil's Foreign Ministry said on Friday its embassy in Caracas had asked the Venezuelan government to provide it with any information that could help it determine whether the attack had happened and whether Brazilians had been involved.

Brazil's National Indian Foundation, a government body that oversees indigenous affairs, said it would seek a joint investigation by officials from both countries at the site.

The border area between the two countries - a long, dense swath of the Amazon rainforest - has increasingly become the site of conflicts between indigenous people, gold miners, and others seeking to tap jungle resources.

The tribe that was allegedly attacked, the Yanomami, says it has given repeated, but unheeded, warnings to Venezuela's government that the conflicts are intensifying.

On Wednesday, Venezuela's public prosecutor said it would investigate. By late Friday, however, Venezuela's government still could not confirm whether the attack had occurred.

Venezuelan Interior Minister Tareck Al Aissami said in televised comments on Friday that officials had managed to speak with seven of the nine known groups of the Yanomami tribe and thus far had no proof of an attack in any of their settlements. Officials, he added, would soon meet with those and the other two groups to further clarify the matter.

"God willing, there won't have been any violence among the other two groups, either," he said.

Native rights groups voiced alarm.

HELICOPTER, GUNFIRE, EXPLOSIONS

In the document presented to Venezuelan authorities this week, Yanomami leaders said tribe members in the area had spoken with three villagers from the community where the attack allegedly took place.

The three villagers, the only inhabitants of the community known to be alive, said they had been hunting away from the settlement when they heard a "tokotoko" - their indigenous word for helicopter. They also heard gunfire and explosions, the document said.

Other Yanomami who visited the village later said a communal hut had been burned and that they found charred bodies and bones.

The attack was the latest in a growing number of conflicts with Brazilian gold miners, the Yanomami said in the document.

The tribe alerted soldiers in the region in late July about the attack and the soldiers interviewed some of the tribespeople who had seen the destroyed village, according to the document. Venezuela's army has not commented.

The remote settlement is a five-hour helicopter flight, or 15-day walk, from Puerto Ayacucho, capital of the southern Venezuelan state of Amazonas.

Because of the distance and isolation of many indigenous settlements, the government is often unable to protect tribes from incursions by outsiders. Much of the violence goes unreported, and follow-up investigations are difficult once conflicts take place.

(Additional reporting by Mario Naranjo; editing by Mohammad Zargham)