CLAYTON -- Clayton police are searching for a suspect in a sexual assault and robbery early today of a 23-year old female student who goes to the University of Missouri St. Louis. Police say he may have robbed two Washington University students the day before.

Washington University issued a crime alert following the robbery of its students on Sunday.

Clayton police said the suspect at about 12:30 a.m. today approached the 23-year old as she left her vehicle in the 7400 block of Byron Place. He displayed a dark-colored semi-automatic handgun, police said. After the attack the suspect ordered the woman to walk home, police said.

The University City and Washington University police departments said the robbery of two Washington University students occurred about 2:45 a.m. Sunday at Big Bend and Lindell Boulevards. The suspect displayed a gun and demanded wallets and cell phones, the university police said. The suspect took a wallet, the university police said.

The Clayton police and University City police have released police sketches of the suspect, who they say is 25 years to 30 years old and about 5 feet 6 inches tall. He matches the description of the suspect in an earlier robbery on Skinker Boulevard in St. Louis, police said.

The police departments say people with information should call Clayton police at 314-645-3000, University City police at 314-725-2211 or Crime Stoppers at 866-371-TIPS.