A number of schools across Sydney simultaneously received bomb threats via phone messages between 10:50 a.m. and 11:10 a.m., prompting an immediate evacuation, the Sydney Morning Herald reported.

The Mona Vale on Sydney’s Northern beaches, Woolooware in Sydney’s South, Richmond and Penrith in Sydney’s West and Lake Illawarra all received the threats.

At least four schools in Melbourne had also reportedly received threatening phone calls this Friday morning. By 2:30 p.m., the threats are deemed to be hoaxes and students are allowed to be back in school, according to the Sydney Morning Herald.

Footage from 7News showed that Penrith High School was now sent into lock down after receiving a bomb threat. In Wooloware High School, Alissa Machione told Yahoo7 what she witnessed. “The cops just blocked both side of the road and we’re getting all the children over to Sharkies leagues club immediately,” Machione said.

The New South Wales Police Spokesperson warns the people behind these bomb threats that threatening is a serious crime. “Police are warning that making such threats is a serious criminal offence and every effort will be made to identify the person or persons responsible.”

“”We are aware that a number of Victorian schools have received a threatening phone call today,” a spokesperson for Victoria Police also said. According to the police, the evacuation is just a precaution. They are still monitoring schools that received similar threatening phone calls in the past 24 hours.

Sought to comment on the issue, the Victoria Department of Education spokesperson told Yahoo7 News that the safety of their students is always their number one priority.

“All schools have emergency management plans which include evacuation plans, and the affected schools have enacted their plans this morning,” the department official said while also reiterating that the institution takes this matter seriously.

The police investigation is still undergoing.