( CNN ) -- A Pennsylvania woman told police she was attacked at an ATM in Pittsburgh by a robber who became angry when he saw a John McCain bumper sticker on her car , a spokeswoman for the Pittsburgh Police Department said Thursday . Police can not confirm whether a man attacked this woman because she had a McCain sticker on her car . Public Information Officer Diane Richard said police can not substantiate her story , however , and the investigation is ongoing . Richard said the 20-year-old told investigators a man approached her Wednesday night at an ATM in the city 's East End , put a blade to her neck and demanded money . She said she gave him $ 60 and stepped away from him , Richard said . But the woman said the man `` became very angry '' when he noticed her car had a bumper sticker supporting the GOP presidential nominee , according to Richard . The woman said he punched her in the back of the head , knocked her to the ground and `` continued to punch and kick her while threatening her , '' the spokeswoman said . Before he left , the woman said , he carved the letter `` B '' into her face with a knife , according to Richard . There was no indication what the `` B '' indicated . The alleged assailant fled on foot , Richard said . `` We , the police , can not substantiate this yet , '' she said . `` This is what she told police . '' The woman , who is not from Pittsburgh , refused medical attention , Richard said , although she told the investigating officer she would see a doctor Thursday . There was no update on her condition , she said . Richard said the woman described her alleged attacker as a dark-skinned African-American , 6 feet 4 inches tall with a medium build and short dark hair , wearing dark clothing and shiny shoes . McCain spokeswoman Jill Hazelbaker told CNN that McCain and running mate Sarah Palin `` spoke to the victim and her family after learning about the incident earlier this afternoon . '' Hazelbaker said the campaign would not offer more detail out of respect for the woman 's privacy . The campaign of Democratic presidential candidate Sen. Barack Obama responded to the report with a statement saying , `` Our thoughts and prayers are with the young woman for her to make a speedy recovery , and we hope that the person who perpetrated this crime is swiftly apprehended and brought to justice . ''
Woman says man robbed her , returned to beat her after noticing sticker on her car . Police say they can not substantiate her claim . Comment: McCain spokeswoman says McCain , Sarah Palin , have spoken with the victim .