AMMAN, Jordan — An assailant stabbed eight people at the popular archaeological site of Jerash in northern Jordan on Wednesday, according to the authorities, who said the man had been arrested. The motive for the attack remained unclear.

Four foreign tourists and four Jordanians — a tour guide, a truck driver, and two police officers, one of whom tried to stop the attack — were wounded and taken to a hospital, a spokesman for the Jordanian police said.

Three of the foreign victims were Mexican, the police said, and the other Swiss. One of the police officers and the Swiss tourist were in serious condition, while the others were in stable condition, the police said.

In a video from the scene that was shared on social media, a woman could be seen lying facedown on the ground as someone pressed a towel against her lower back. Another man sat nearby, his leg and shirt covered with blood.