* Convoy of Canadian miner Semafo attacked on Wednesday
* Relatives beg authorities for more information
* Twenty-nine bodies identified
* Burkina Faso struggling with 3-year insurgency
(Adds another victim's testimony)
OUAGADOUGOU, Nov 8 (Reuters) - A mine worker shot during an ambush on a mining convoy in Burkina Faso said on Friday he was one of only three survivors from a bus with up to 80 people aboard, suggesting the death toll may be much higher than officially reported.
Abel Kabore, 35, described the attackers, some speaking a foreign language and shouting "Allahu Akbar" - Arabic for "God is great" - raking three buses with bullets after a security vehicle escorting the convoy hit a landmine.
The first two buses were able to escape, he said.
"The three buses which were shot ... there were so many dead. It was over 100. We were on the ground. We saw everything," he said quietly at a hospital in the capital Ouagadougou. Of the people on his bus, "only 3 of us survived."
Another survivor, who worked for Australian mining services provider Perenti, said he was in the fifth bus, about a km (half a mile) from the vehicle hit by the explosion.
The gunmen fired at the bus for an hour, he said, then came aboard to execute survivors.
"These were the last prayers we were praying," he said, asking not to be identified for security reasons. "I pretended I was dead - that was all I could do."
When he was finally able to leave the bus, he had to climb over the dead bodies of his co-workers. "I saw one body facing up. I knew him. He looked untouched and I called out to him but he didn't answer. Then I touched him and I knew he was dead."
A security source who works in the sector and a worker at the mine previously said the convoy was likely carrying around 250 people in all, leaving dozens unaccounted for based on the authorities' casualty list of 38 dead and 60 wounded.
Neither Canadian gold miner Semafo SMF.TO nor the Burkinabe authorities have confirmed how many people were in the convoy when it was ambushed on Wednesday on a road leading to the company's Boungou mine in eastern Burkina Faso. responded to queries on Friday.
Perenti has said 19 of its workers were killed in the attack and 20 sent to hospital. The employees worked for its African Mining Services unit, which had been contracted by Semafo for work at its Boungou mine.
Panicked workers tried to flee the buses during the attack, then desperately scrambled back onboard away from gunmen in the bush, said another wounded survivor, Bakary Sanou.
"People were trying to go back into the buses. I tried to run away into the bush, and saw that they (the attackers) went back onto the buses, opened the doors and tried to kill everyone," said Sanou, an oversize bandage on his right foot. A mobile phone lay charging next to him on rumpled pink sheets.
IDENTIFYING VICTIMS
The bodies of 29 victims were formally identified on Friday, public prosecutor Harouna Yoda said in a statement, adding that their families would be allowed inside the morgue of the Bogodogo District Hospital in Ouagadougou.
Distraught and angry relatives had complained earlier that authorities were not letting them view the bodies.
"The government should allow at least one family member to go and identify a body," one man, Ismail Roamba, told Reuters.
It was still unclear who carried out Wednesday's ambush. Yoda said the government had opened an investigation.
A homegrown, three-year-old insurgency has spread over parts of Burkina Faso, amplified by a spillover of Islamist militant violence and criminality from its chaotic northern neighbour Mali.
In 2016, an Islamist attack on a hotel and restaurant in the capital killed 30 people. A similar assault the next year killed 19. In 2018, militants hit the French Embassy and the army headquarters in Ouagadougou, killing 16.
The Boungou mine is located in Burkina Faso's eastern region about 355 km (220 miles) from Ouagadougou. Semafo has said the mine site is secured, but it has suspended operations there.
Canada condemned the attack and offered condolences to victims. "Canada remains concerned about the deteriorating security situation in Burkina Faso and deplores the violent attacks carried out on civilians," its foreign ministry said.
"We will continue to work with Burkina Faso and partners in the region to prevent conflict and fight terrorism."