A senior Jordanian police officer was killed during protests in Jordan's southern city of Al Husseiniya, in Maan province.
Col Abdul Razzaq Al Dalabeh, the deputy director of Maan's police force, was shot in the head, the Public Security Directorate said on Friday.
Two other officers were also wounded during the protests, which police blamed on “a group of vandals and outlaws”.
“We will strike with an iron fist anyone who attempts to attack the lives and public property or threaten the security of the homeland and its citizens,” police said.
“Will not allow criminals and vandals to exploit this circumstance to harm the lives of citizens and terrorise them.”
Lorry and public transport drivers have been protesting against low wages and a sharp increase in fuel prices.
Earlier this week, the Bus Owners' Association and the Transport Services and Taxi Owners' Union reached an agreement to end their strike after the government agreed to provide cash subsidies.
However, clashes between security forces and civilians continued in the industrial city of Al Zarqa, Jordan's second-most populous city, witnesses told Reuters.
In Amman, people staged anti-government protests in the district of Tafiyla while others burnt tyres on a major motorway connecting Amman and the Dead Sea, witnesses said.
In an interview on Jordan's state television on Thursday, Minister of State for Media Affairs Faisal Shboul said dialogue with the striking parties was continuing, with the government having offered them “solutions that fulfil many of their demands”.
However, he said the current situation negatively affected “economic life in this country”.
“You have the right to strike but forcing others to do the same, or attacking other vehicles, some of which are for tours, is not acceptable and not within anybody's right,” Mr Shboul said.