A U.S. Border Patrol agent nearly lost his thumb in a Christmas eve attack when an illegal immigrant bit his digit during an altercation in Ajo and “pretty much gnawed his finger down to the bone,” according to union officials.

Border Patrol officials have released few details on the incident, but union president Art Del Cueto told Fronteras the agent was attempting to arrest the man near the Arizona border and was forced to call for reinforcements when he decided to fight back.

“It was a back-and-forth fight. The agent almost got his thumb completely gnawed off,” Del Cueto said. “The illegal alien fought him, two other agents showed up and he got in a fight with the other two agents.”

A Border Patrol statement omits the gruesome details.

“On Dec. 24, a Tucson Sector Border Patrol agent attempted to arrest a suspected illegal immigrant in a remote area near Lukeville, Arizona, when the suspect became assaultive toward the agent,” the official statement read. “Two more agents responded to assist and the suspect was arrested. All three agents and the suspect were transported to a local hospital, treated and released. The suspect is being held on immigration violations.

“Assault charges are pending the outcome of the investigation,” according to the Border Patrol.

Del Cueto told the news site the agent’s injury was serious enough that he’s still recovering from the incident.

“I’ve talked with him, I’ve heard he has some damage still. He doesn’t have feeling in his thumb yet but from speaking to the agent, the agent did explain that he pretty much gnawed his finger down to the bone,” he said. “The agent tried pulling his finger from his mouth and the guy just clamped down tighter.”

Border Patrol data shows agents endured 585 assaults in Fiscal Year 2016, which ended in September. Those figures are up significantly from 477 the year prior.

The incident highlighted by Del Cueto came a week after an agent shot a man in the leg who took his baton in a struggle and attempted to use it against him, and a few days before two people shot at Border Patrol vehicle Dec. 30, Frontera reports.

Regardless, agents continue to put their lives on the line to protect and save illegals flooding across the border. In Calexico, California, agents on Wednesday rescued a woman from drowning in the All-American Canal in an isolated area about 32 miles east of the Calexico West Port of Entry, U.S. Customs and Border Protection reports.

The woman, a 29-year-old Mexican national, scaled a fence along the border and fell into the canal, where agents with the El Centro Sector and Yuma Sector, with help from the Imperial County Fire Department, quickly pulled her from the water.

“The selfless actions of our Border Patrol agents pulled this woman from a dire situation,” Chief Patrol Agent Rodney Scott said. “It also demonstrates our commitment to the sanctity of all human life.”

The woman was taken to the hospital for hypothermia before she was returned to the El Centro Sector station for processing, according to the agency.

So far in the 2017 Fiscal Year agents have rescued six people from the canal.