Los Angeles County sheriff's officials on Friday were seeking witnesses and any other victims amid a search for a suspect or suspects in the crimes. It was not yet known whether the attacks were related.
The South El Monte assault took place about 5:30 p.m. Thursday at the Whittier Narrows Recreation Area, located in the 500 block of Durfee Avenue.
The woman was going for a run on the trail when a suspect approached her from behind. He pulled her into some bushes and sexually assaulted her, according to press release from the LASD.
The victim was able to eventually fight the suspect off and escape.
The suspect fled the scene on his bike toward Durfee Road and out of view, officials said.
The suspect is described as a Hispanic man, approximately 20 to 30 years of age, with light skin and a black faded haircut, 5 feet, 9 inches tall and weighing about 175 pounds. He was wearing a black T-shirt and black sweatpants and has a teardrop tattoo under his left eye.
A similar attack happened on the same night just three hours later. In this incident, a woman jogging in Lake Balboa was approached by a man with a knife who robbed her of her cellphone, threw her into tall bushes and told her, "If you scream, I'll kill you," according to Los Angeles police.
The victim feared she was going to be raped and fought back. Police said the suspect kicked her several times and threw her over a fence before fleeing on the bike path.
Anyone with information on either incident was urged to call police.