KUALA LUMPUR - Malaysia's Immigration Department has said it will be stepping up enforcement to prevent people from crossing illegally from Johor to Singapore.

Authorities have in recent weeks arrested dozens of people for taking a "shortcut" that bypasses the Johor Customs, Immigration and Quarantine (CIQ) complex to enter Singapore. Those detained were walking along railway lines at the Causeway to Singapore.

"What we are doing now is to take preventive measures to educate the public, but stern action will be taken after this," the department's Director-General Datuk Mustafa Ibrahim said, according to Bernama.

The Star reported last month that some commuters trying to avoid the morning traffic jam had been using the 300m bypass route for some time.

Since the Malaysian passport is electronic and does not need to be stamped, Singapore immigration officers are not alerted if the passport holder bypasses the Johor CIQ. The databases of the Malaysian and Singaporean immigration authorities are not linked.

According to the department, some 54 people have been detained for taking the shortcuts and sneaking out to Singapore after the department began its crackdown on the illegal crossing last month.