MAE SAI, Thailand — The mission to save 12 boys and their soccer coach missing for six days in a flooded cave complex in northern Thailand experienced a setback on Friday when at least three rescuers near the entrance appeared to suffer electric shocks.

The incident most probably caused by jerry-rigged electrical lines fed into the caverns to power lights and pumps. Journalists saw workers run out of the cave shouting that some rescuers had been injured and to shut off the electricity immediately.

Ambulances quickly arrived and witnesses saw three men being carried to them on stretchers. Police said their injuries were minor and the men were in stable condition.

Chiang Rai province Gov. Narongsak Osatanakorn, however, later said the incident was a misunderstanding, and all that had happened was that a worker had fainted from exhaustion after long hours without eating. There was no immediate explanation of the discrepancy in explanations.

The governor has come under criticism that he has mismanaged the rescue effort.

Thailand's prime minister also visited the cave on Friday and urged relatives not to give up hope.

"There has to be faith. Faith makes everything a success," Prime Minister Prayuth Chan-ocha, the country's military ruler, told families waiting outside the cave. "Faith in the actions of officials. Faith in our children who are strong and vigorous. Everything will go back to normal."

The boys, aged 11 to 16, and their coach entered the sprawling Tham Luang Nang Non cave after a soccer game on Saturday afternoon, but near-constant rains since then have thwarted the search for them.

Authorities have nevertheless expressed hope the group has found a dry place within the cave to wait, and that they are healthy enough to stay alive.

Muddy floodwaters reached near the cave's entrance Friday despite days of efforts to drain the water. Rescuers kept working outside, trying to find hidden shafts in the green mountainside to access the cave complex.

Rescuers are working to drill wells in hopes of draining the water, which could allow divers to advance into flooded passages. Despite the hard work, progress has been fitful at best, with no guarantee the water will soon recede with months left in Thailand's rainy season.

Gov. Narongsak thanked people in Thailand and abroad for their support, including a U.S. military rescue team and U.K. cave divers.