The body of a Mexican teenager who went missing this month in the northern state of Nuevo Leon has been found submerged in a cistern inside the grounds of a motel near where she was last seen alive, authorities said on Friday.

Debanhi Escobar, an 18-year-old law student, vanished on April 9 amid a spate of disappearances of women in Nuevo Leon's capital Monterrey that has sparked protests and intensified international scrutiny of gender violence in Mexico.

Twenty-six women and girls have disappeared in Nuevo Leon this year, and five more have been found dead after being reported missing.

“The body found is Debanhi’s, and the cause of death is a profound contusion to the skull,” state attorney general Gustavo Guerrero said in a Facebook live video. All lines of investigation are open, he said.

Guerrero’s comments came as hundreds of women blocked a highway in downtown Monterrey, paralyzing traffic, demanding an end to gender violence.

The protesters demanded the resignation of the state secretary of security, Aldo Fasci, and carried signs with the names and faces of Debanhi and other local women who have gone missing or been found dead recently.

"I'm here for all the daughters of Nuevo Leon, because we want a state that's safe and free for them," said Adriana Flores, 45.

Debanhi was last seen alive standing next to a highway, in a photo snapped by a driver contracted to take her home after a party.

Her father, Mario Escobar, on Friday accused the driver of trying to grope his daughter's breasts, citing video camera footage, suggesting this is what led her to get out of the car. What happened after she exited the vehicle is unclear.

In an interview with local media, Escobar accused authorities of mishandling the investigation.

"My daughter is dead because of incompetent (authorities), and because of sexual harassers," he said.

The state attorney general’s office told Reuters that in the course of the case’s investigation it would be determined whether any errors were made, voluntary or involuntarily, during the search for Debanhi.

The governor, Samuel Garcia, said this week that the local government had mobilized additional resources in the search for Debanhi and other missing women.

The driver could not be reached for comment.

Mexican President Andres Manuel Lopez Obrador gave his condolences to the family on Friday and said the teenager's death could be investigated by the federal attorney general's office at the family's request so that there are "no doubts" over the case.