A 70-year-old man has been charged with mischief after calling 911 to complain about an Amber Alert for five missing children.

Hamilton police, who claim the man was trying to "purposely tie up" emergency lines, say they believe it's the first time someone in Ontario has been charged for calling to protest one of the emergency broadcasts.

The man called 911 at 5:04 p.m. ET Tuesday, a few minutes after the alert went out, according to Acting Det. Sgt. Lisa Chambers, who said it quickly became clear the man didn't have an emergency to report.

"Simply put, he was angry about receiving the Amber Alert on his phone because he was trying to rest," she said. "And then he further told us he would continue to call in response to the ongoing alerts."

The alert was issued Tuesday afternoon by Niagara Regional Police after five children went missing and officials said they had concerns for the siblings' safety.

The children were found safe Wednesday, according to police, who credited the alert with providing information that led to them being discovered.

Investigators in Hamilton identified the man, arrested him and charged him with mischief. He is scheduled to appear in court on Oct. 15.

Amber Alerts are federally mandated emergency broadcasts sent to wireless devices across Ontario every time police issue an alert concerning a missing child believed to be in imminent danger.

Every alert in Ontario this year has been followed by backlash, though the broadcasts also have plenty of supporters.

Police say 911 is for emergency calls only. (Dan Taekema/CBC)

A petition is calling for the Ontario government to fine people who call emergency dispatchers to complain about broadcasts of Amber Alerts.

Chambers said she's aware the broadcasts can wake people up or startle them, but it's important to understand that police have to follow strict guidelines when issuing an alert, and they're ultimately meant as a tool to keep children safe.

'It's very frustrating'

As for the complaints that continue to roll in, Chambers said, Hamilton police hope the arrest will show people that calling emergency lines to vent frustrations can come with consequences.

"It's very frustrating … I never thought the day would come where I'd have to explain to an adult the importance of not tying up a 911 line and the importance of an Amber Alert … in locating a child who may be in danger."

She said police feel they have a "solid case." It's now up to the court system to decide what should happen.

"It's unfortunate that there is a first, that we even have to proceed with charges and that people are calling in to complain about the Amber Alerts."