The attackers are reportedly hiding within the grounds of Karak Castle, a Crusader fort, in the mountainous city, around 70 miles south of the capital Amman.

Special Forces have been deployed to hunt the shooters down, with security sources not ruling out a militant attack.

Four of those killed were police officers and the other two were reportedly Jordanian civilians.

Several tourists were believed to have been taken hostage by the gunmen, who took refuge in the Castle, however they were later released.

Security officials are not ruling out the possibility that the shooting was a coordinated militant attack.

The Public Security Directorate said that events began when a police patrol received reports of a fire at a house in the town of Qatraneh, in the Karak district.

When the officers arrived, they were shot at by people inside the house.

Two officers were injured and the shooters fled in a car.

In another attack, gunmen shot at a security patrol in Karak but nobody was hurt.

The third attack saw armed men open fire on a police station in Karak Castle and, according to the security directorate's statement, five or six gunmen had taken refuge inside the castle.

So far, no group has claimed responsibility for the attacks.

Karak is a popular tourist destination in Jordan, a country which has been part of the US-led air campaign against Islamic State militants in Syria.

But many Jordanians oppose the country's involvement, which they say has raised the security threat at home and caused the deaths of fellow Muslims.