The Egyptian authorities said on Thursday that they were investigating a video of a woman being attacked by a mob of men that has ignited widespread outrage over the country’s longstanding problems with sexual violence.

The video, which shows a group of men swarming around a woman, grabbing at her as she screams and struggles to get into a car, surfaced online on Wednesday. Activists said it was recorded in the city of Mansura, north of Cairo, though it was not immediately clear when, except that it was night.

It was also not clear who the woman was or what happened to her after she got into the car.

At least seven people were arrested in connection with the attack, according to the news site Al Masry Al Youm.

Ragia Omran, a human rights lawyer in Cairo, said there had been outrage on social media in response to the video.