An underground tunnel was found near a Florida bank. The FBI was called in but even they were stumped

The FBI is investigating after an underground tunnel leading to a Florida bank was found – but officials have no clue who dug it or when.

FBI special agent Michael Leverock told reporters Wednesday that public works employees in Pembroke Pines got a call the previous night about a sinkhole in a road near a Chase Bank branch.

After an entrance near a wooded area and some equipment was found, Pembroke Pines police called in the FBI.

"This is truly a unique case here," Leverock said. "I would like to say that I saw something like this in movies, however, this hole is so small that – it's unique."

The tunnel is no more than 2- to 3-feet in diameter and "very claustrophobic," Leverock said. He estimated the entrance was about 50 yards from the bank, and said officials were still digging but that whoever was responsible did not penetrate the bank.

Authorities also found a power cord, a winch, a small generator and other items the FBI did not reveal near the entrance.

Leverock said the tunnel's diggers appeared to have used pick axes and wagons to clear the dirt, but many questions remain about how the hole was dug given its size. 

"I don't know how they did it. I would like to put it into words for you. But it is so cramped in there, and that wagon is – I mean it's a puzzle. I can't imagine how they did it," he said.

No bodies were found, no arrests have been made and Leverock said he wasn't certain when the tunnel was last worked on. "I'd like to talk to 'em," he repeated.

One thing Leverock did say with certainty: "They were heading towards the bank, and that's for sure."

The FBI is asking anyone with information to call 754-703-2000. 

Follow USA TODAY's Ryan Miller on Twitter @RyanW_Miller