Investigators are looking for a man who tackled a woman who was jogging on the Blunn Creek Greenbelt on Monday afternoon, Austin police said.

The man stated he had a gun, but no gun was observed, police said. The woman was able to get away and report the attack.

Police are looking into whether the case is related to an incident in which a naked man said he had a gun near Travis Heights Elementary School, which prompted the school to place the campus under a lockout for about an hour Monday, officials said. The school incident happened around 3 p.m., and the attack on Blunn Creek happened a short time later, police said. No gun was observed in the school incident, either.

In the school incident, the man was described as 5-foot-8, skinny, with dirty blond hair and a goatee, police said. In the Blunn Creek incident, the man was described as stocky, about 30 years old, 5-foot-8, dark-haired and wearing a white T-shirt.

"We do ask that the community remain vigilant and if you see something that looks suspicious, call 911 immediately," Austin police said in a statement.

Anyone with information about either of these incidents can call Austin police's sex crimes tip line at 512-974-5095.