Bureau of Immigration chief Norman Tansingco has ordered a tighter screening of arrivals from Cambodia and Vietnam.

Tansingco said a recent uptick in criminal cases involving people from said countries touched off the extra effort that will be exerted to screen potential troublemakers.

Aside from Chinese nationals, some workers from illegal online gambling companies were found to have come from Cambodia and Vietnam.

The newly appointed BI chief said it's routine for immigration authorities to look at arrival trends and to look for patterns, including those involving the transit of individuals who need additional vetting.

He said their partnership with other law enforcement agencies allows them to see whether there is a need to tighten measures on certain types of travelers.