Najib said this when asked to comment on an incident where a Domestic Trade and Consumer Affairs enforcement officer was injured after being assaulted by a group of Thais who are believed to be diesel smugglers.

The Star reported earlier a Malaysian enforcement officer at the Bukit Kayu Hitam checkpoint suffered cuts and bruises when a rowdy group of Thai nationals, who were prevented from crossing into Malaysia, attacked him on Saturday.

Three other enforcement officers managed to run for cover when accomplices of the attackers chased them.

Domestic Trade and Consumer Affairs enforcement officer Aswadi Abdullah, 27, said he was attacked with metal rods and nail-studded bats in the 10.45am incident.

He said there were about 20 foreigners and about six people attacked him.

The others went after his colleagues, he said at the Jitra Hospital, near here.

"I tried to fight off my attackers with one of their bats," he said, adding that the assault lasted more than a minute.

He said his attackers also smashed his car.

He said the Thais made a ruckus at the bus parking lot on the Malaysian side of the border before escaping back into their country.

It was not immediately known how they managed to flee past the border checkpoints without anyone stopping them.

Aswadi said that about 30 minutes before the attack happened, he and his three col-leagues had disallowed a pick-up truck from entering the country on suspicion that the visitors were involved in diesel smuggling.

"The driver and his passengers, shouting in Thai, seemed to threaten us," he said, adding that the group then left the place.

"However, we had a tip-off that they were returning to attack us. So we quickly ran to my car, which was at the parking lot. But it was too late. The gang spotted us."He added that onlookers might have thought it was a personal clash and chose not to come to their help since he and his colleagues were not in uniform at the time.

State Domestic Trade and Consumer Affairs deputy director Razali Lebai Salleh said the attackers fled back into Thailand via the bus route.

"Our officers had received threats before. But this is the first time we faced physical assault," he said.

The state Bernama news agency reported Kedah state's Chief Minister, Mahdzir Khalid, as saying earlier that the offenders had to be prosecut-ed even though they were foreigners.

Calling for swift action, he said he was concerned foreigners had been able to easily enter the country and attack a government officer.

"I'm also worried that the attack might lead to tension at the border. I hope the authorities closely watch the situation," he was quoted as saying.

Malaysian border officials and police said they were investigating the incident.

Malaysian fuel subsidies mean prices are low compared with the rest of the region, tempting smugglers to sell diesel in neighbouring Thailand, where it is more expensive.

The Star/Asia News Network