The directorate of general security in Jordan said a number of tourists, a tour guide and a security officer were stabbed in the attack in Jerash.
Foreign tourists were among eight people injured in a stabbing attack in the Jordanian city of Jerash, the country's public security directorate has said.
In a statement, the directorate said four Jordanians, three Mexicans and one Swiss national were among those injured.
In a statement to Euronews, the Swiss Federal Department for Foreign Affairs said they were aware of the knife attack and their representation in Amman is assisting the Swiss victim.
Early reports had indicated that the victims were Spanish citizens, but Spain's foreign minister said this was not the case.
Footage captured after the attack was later shared across social media, and showed one person lying on blood-soaked ground as another appeared to use a cloth to place pressure on a wound to the back.
Another person, also covered in blood, was seen sitting on a nearby wall.
Natalie, who witnessed the scene, said she and her tour group of American citizens were close to the Roman city’s hippodrome before a guide told them there had been an "accident".
"We came out [and] we saw the crowd and blood. I thought it was a fight. There wasn’t even police tape and people weren’t treated yet."
Speaking to Euronews, Natalie said, "you could have walked through the blood ... [later] police were running around."
Natalie added she and her husband were "shook" when they later saw police standing near a machete on the ground, but it is not known if this was connected to the stabbings.
In a thread on Twitter, another witness described the "shock" he felt.
He added that the attacker appeared to be dressed in "black, militant gear, including head covering".
Speaking to Reuters, bus driver and eyewitness Ali El Agrabawi said he was stabbed after leaning towards a man carrying a knife when the group was stopped at a cafeteria.
"He passed in front of me and I leaned towards him. I slipped, and he stabbed me. I then backed away, moving towards the policeman. He gave the policeman a slight stab. I tried to attack him from behind. I pushed him to the ground. Afterwards, all the policemen came and took him."
In an earlier statement to Facebook, the security directorate said one person had been arrested after the attack and that investigations had since been launched.
The spokesperson added that all the injured are still receiving treatment and their condition is all "moderate", except for a Jordanian security official and one Mexican tourist, who were described as "critical".
Mexico's Foreign Affairs secretary has tweeted that the three Mexican tourists injured were on a guided tour of the city of Jerash.
Speaking at a hospital near Jerash, the Jordanian Minister of Health Saed Jaber said that the situation has been controlled, and both cases are stable."
"Two cases were transferred by helicopter to King Hussein Medical City after contacting them, because they need specific, or possible, rearrangement."
The British Embassy is in contact with local authorities and urgently seeking information for tourists following the incident.
Jerash, a city situated north of the Jordanian capital Amman, is an area popular with tourists due to the ancient Roman settlement located on the outskirts.