SINGAPORE — Several international schools across the island issued safety alerts to parents and students, triggering widespread concerns, including on social media, following two separate incidents of female students being asked by strangers to board vans on Jan 11 and 16.

Police reports were lodged and there was a heavier presence of cops at some of the schools but the police appealed to the public not to speculate while it looked into the incidents.

And it turned out to be a false alarm for at least one of the cases: The police said on Wednesday evening (Jan 17) that one of the van drivers hauled up for questioning had "no ill intent". The male driver was involved in the Jan 11 incident with a United World College (UWC) Middle School student. TODAY understands that he was trying to offer a lift to the girl as it was raining.

Investigations are still going on for the other unrelated incident, which involved a woman driver and a Tanglin Trust School (TTS) student.

International schools, parents and students, meanwhile, have taken precautions such as stepping up patrols, advising students on how to respond in similar situations and not walking without company near the campuses.

UWC told TODAY it has informed parents via email to remind their children "how to keep themselves safe in situations such as these".

They should ignore the stranger, walk away, and tell a known adult about it.

"In addition, as part of the Personal and Social Education programme, and in keeping with our child safeguarding policy and practices, we spoke to students in age-appropriate ways about keeping themselves safe in these situations," a UWC spokesperson added.

Meanwhile, Tanglin Trust School said all parents were informed of the incident on Jan 16. The school suggested students "should not walk alone in the vicinity of the school but walk with friends".

"Tanglin Trust School students were reminded the same day of how to stay safe and what to do if they are approached at any time by a stranger," said a TTS spokesperson, adding that it had requested "higher police presence" around the school vicinity, located near one-north.

At least three other international schools said they have issued similar alerts to parents and teachers.

A spokesperson for ISS International School said it sent out a circular to parents and the school community in light of the incidents. Its security team has stepped up patrols around the campus, located near Depot Road, especially during the arrival and departure of students.

Teachers have also spoken to students on topics like recognising an unsafe situation, how to respond immediately, and who they should tell once safe.

It was the same at Chatsworth International School, which issued an alert to parents and teachers reminding them to "be more vigilant and take the necessary steps to minimise any risk to the children".

Mr Andre Casson, Head of School at the Australian International School, told TODAY the school "shared broad details and a general personal safety reminder with our own parents and staff".

A Singapore American School spokesperson said it is in contact with the Singapore police and it works "regularly with the United States Embassy regional security office" in the Republic. The school had an increased police presence just outside of its campus on Wednesday, the spokesperson added.

Some parents and students at UWC and Tanglin Trust School said they were rattled by the incidents, but took it in their stride.

A 14-year-old UWC student, who only gave his last name as Li, said the incidents were "shocking".

"Singapore is a pretty secure and safe country, so it's quite shocking something like this could happen," he said.

The school spoke to its students last week during a school assembly about the incident, and there were in-class discussions about it again on Monday, he said.

A housewife at Tanglin Trust School, who wanted to be known as Ms Soriano, said she reminded her son, 10, and daughter, 13, not to speak to suspicious strangers.

The 41-year-old, who was picking up her children, said she was scared by the incident and would be more vigilant.