Officials investigating an apparently extensive case of sexting at a southern Colorado high school are urging parents to check their children's phones for explicit selfies and talk to them about the risk of the photos becoming public.

Canon City High School gave police one phone with several hundred images that investigators will work to identify, police Chief Paul Schultz said Friday.

An unspecified number of students have been suspended. Superintendent George Welsh wouldn't discuss how long those suspensions would last to protect the students' privacy.

Enough football players were involved that the school forfeited its final game of the season this weekend because officials did not think the team should represent the community. The district has said that both girls and boys are involved in the sexting.

The investigation began Monday after some people contacted school officials and a tip came through a state student safety hotline. Few details have been released about the extent of the sexting at the school of 1,000 students.

Police distributed a bulletin to parents telling them about apps that can be used to hide photos on phones and urging them to talk to their children about the risk of explicit photos being shared through social media.

The school is offering a counseling hotline to students worried about getting in trouble for sexting. Welsh emphasized that, while some may face serious consequences for what they have done, prosecutors will use "common sense" in deciding whether anyone should face criminal charges.

District Attorney Thom LeDoux said he would focus on whether anyone was coerced into sharing photos, whether any adults were involved and whether there was any corresponding sexual contact.

The possession of explicit photos of minors is a felony in Colorado, which, like many states, has not updated laws intended to fight adult exploitation of children for the smartphone age. Convictions can carry a requirement to register as a sex offender, but LeDoux said he would only pursue that option if it was in the best interest of the community and possible victims.

Jeff Temple, an associate professor and psychologist at the University of Texas Medical Branch at Galveston who has studied sexting, said his research found that a sizable minority of teens — 28 percent of both girls and boys — send racy text messages. They are more likely to be having sex than teens who don't sext, but there's no evidence that sexting is a sign of poor mental health or other problems, Temple said.

He doesn't like the idea of parents snooping on their high-schoolers' phones. He thinks teens will be ahead of their parents on using technology to cover their tracks anyway.

Instead, he said parents should talk to their children about healthy relationships and sex and avoid trying to scare them about the possibility of explicit images becoming public.

"More kids are having sex in person than they are sexting," he said.