A Texas National Guard member serving at the U.S.-Mexico border was arrested Monday for allegedly sexually assaulting a female colleague in a motel this week, authorities said.

Luis Carlos Ontiveros, 30, was taken into custody in Alpine, about 70 miles from the border, The Dallas Morning News reported.

The woman told police that she had been drinking with Ontiveros. He offered to take her back to her motel room, according to an affidavit obtained by Midland's KOSA-TV. The woman alleged that he began kissing her, then removed her clothes and touched her.

The woman, who is also a member of the National Guard, said she fled after Ontiveros told her he would perform oral sex. A witness told police the woman knocked on his door, saying Ontiveros had tried to rape her.

Ontiveros was released Tuesday on $20,000 bond. A message from the AP left at a number listed for Ontiveros was not immediately returned.

The Texas National Guard confirmed that Ontiveros was serving in a mission launched in April following President Donald Trump's call for the National Guard to go to the border.

The Guard said it would cooperate with authorities in Alpine, a remote West Texas town in the region of Big Bend National Park.

Laura L. Lopez, a Texas Military Department spokeswoman, told The Daily Beast that the agency would be investigating.

"We are taking these allegations very seriously and will be opening up an inquiry into what happened," Lopez said.

The Associated Press contributed to this report.