The next time you’re standing at the edge of a scenic cliff or on top of a waterfall, take care when you have the urge to snap a quick selfie. It could very well be the last thing you do.

More than 250 people worldwide have died while taking selfies in the last six years, according to a new study from researchers associated with the All India Institute of Medical Sciences, a group of public medical colleges based in New Delhi. The findings, which analyzed news reports of the 259 selfie-related deaths from October 2011 to November 2017, were published in the Journal of Family Medicine and Primary Care.

Of the 259 deaths, researchers found the leading cause to be drowning, followed by incidents involving transportation — for example, taking a selfie in front of an oncoming train — and falling from heights. Other causes of selfie-related death include animals, firearms and electrocution.

“The selfie deaths have become a major public health problem,” said Agam Bansal, the study’s lead author.

Though the study found India to have the highest number of deaths of all countries, numerous reports of fatal selfie incidents have also come from Russia, the United States and Pakistan. Bansal noted that while the simple act of taking a selfie isn’t deadly, the hazard arises when people take risks while trying to get that perfect shot.

“If you’re just standing, simply taking it with a celebrity or something, that’s not harmful,” he said. “But if that selfie is accompanied with risky behavior then that’s what makes the selfies dangerous.”

Bansal added he was also concerned about how many of the selfie-related fatalities involved young people. More than 85 percent of the victims were between the ages of 10 and 30, Bansal said.

“They form the future of a nation,” he said. “They haven’t even realized what their goals are. They aren’t even sure what they want to do. They’re just beginners in their lives.”

One possible way to prevent selfie deaths would be “no selfie zones,” Bansal said, banning them in certain areas such as water bodies, mountain peaks, and at the top of tall buildings.”