Malaysia is tightening security on its border with Thailand, restricting entry and banning Thai motorcycles after an attack on a Malaysian border official.

Thai nationals are currently allowed unrestricted movement within two kilometres of the porous border in a measure aimed at boosting trade.

But Deputy Internal Security Minister Johari Baharum reportedly said that from Jan 1, Thais will need passports to enter Malaysia, and their vehicles must meet Malaysian registration regulations.

Thai-registered motorcycles will also be banned from entering Malaysia.

"There are those who have misused this privilege and have entered further into Malaysia," Johari said of the two-kilometre rule.

"We have also banned motorcycles from coming into the country," he was quoted as saying in the Star daily.

Come and go as they please

Johari said the moves were triggered by the attack on a Malaysian official by a group of Thai men earlier this month.

"At present, (Thais) are free to enter and leave just by raising their hands (to immigration officers on duty)," Johari told the state Bernama news agency.

"They are free to go wherever and do whatever, including crime, in Malaysia and when these things happen, we cannot trace them because there is no record of them having entered the country," he said.

Johori on Sunday ordered border officials to stop skipping over the border for meal breaks and shopping outings, saying the practice was contributing to lax security.

Southern Thailand is gripped by a separatist insurgency which has left more than 1,700 people dead since January 2004.