The attacker who has posed as a police officer and a census taker in a series of attacks on Asian women in the north suburbs has struck again, this time near Glenview, police said.

A 36-year-old woman, who lives in the Dearlove Manor apartment complex in unincorporated Northfield Township, was pistol-whipped and sexually assaulted around 3:20 p.m. Wednesday, officials said. She was treated at Glenbrook Hospital, said Penny Mateck, spokeswoman for the Cook County Sheriff's Department.

An infant in the home during the attack was unharmed, officials said.

Sheriff's investigators on Thursday were working on an advisory bulletin to be distributed throughout the area, Mateck said. The attack marks the sixth home invasion since April 7 in which a man has posed as a police officer, an FBI agent or a census taker before being allowed into a home.

The Sheriff's Department will enter a joint investigation launched by the FBI and police in Chicago and four suburbs where previous attacks took place.

"It sounds similar in that it's an African-American man, wearing similar dress," Mateck said. "He flashes a badge. It's occurred in the same general area. And the victim is an Asian woman."

In Wednesday's attack, the man knocked on the woman's door, produced a badge and told her he was investigating a noise disturbance, officials said. When she opened the door, he forced his way in, displayed a small gun and demanded money. When the woman did not comply, he pistol-whipped her.

The attacker took the woman's infant into another room before handcuffing the victim and sexually assaulting her, officials said. Afterward, he removed the handcuffs, tied her with a belt and fled.

The man is described as being in his 30s, about 6 feet tall with a thin build and black hair. He wore a dark blue shirt and pants and a dark baseball cap, officials said.

Other attacks have occurred in Chicago, Morton Grove, Mt. Prospect, Niles and Skokie. In four of the attacks, the women were of Asian descent. The Morton Grove victim was a Hispanic woman who may have looked Asian, officials said.

Des Plaines police also are investigating whether there is a link between the home invasions and the Nov. 30 slashing death of a Korean flight attendant, Young Kavila, in her Des Plaines apartment.

Asian-American community leaders on Thursday urged police to step up efforts to catch the suspect.

"This type of crime is abhorrent, and the fact that they appear to be racially based is an outrage," said William Yoshino, a member of the Illinois Asian American Hate Crime Network.