Kubang Pasu District Police Chief, Supt Abdul Rahim Abdullah said all the illegal immigrants, aged between 20 and 38, were detained while trying to get out of the country via the Malaysian-Thailand border through illegal routes.
"These illegal immigrants, 18 men and two pregnant women are believed to have worked as farm and construction workers in Butterworth, Penang," he said in a statement.
The two women were later taken to the hospital for a medical check-up.