SINGAPORE - The police have issued an advisory warning travellers against misusing their boarding passes.

In a statement posted on Facebook on Sunday morning, it said that nine cases of Misuse of Boarding Pass had been reported at Changi Airport since January this year.

Thirteen people have also been arrested in connection to offences under the Protected Areas and Protected Places Act.

"The transit areas of Changi Airport are gazetted as Protected Places," the statement said.

"Police would like to remind all passengers who enter the transit hall with a boarding pass should only be there for the purpose of travelling to their next destinations.

"Those who abuse their boarding pass to enter the transit areas to meet friends and/or celebrities, with no intention to proceed to their next destination, are liable for an offence under the Protected Areas and Protected Places Act."

If convicted, offenders could be fined $1,000 and jailed for up to two years.