Police in Birmingham, England, are investigating a series of needle attacks on women.

According to News.Sky.com, detectives said six cases that have occurred in the past six months could be linked to a man seen in a video surveillance image released last week.

"We have also received reports of six further attacks going back over the last six months which could possibly be linked to the same suspect," Detective Inspector Julie Woods said.

The man is seen in a picture taken shortly after a victim felt a sharp pain in her thigh while in the city center on Nov. 3.  The injury was later confirmed as a puncture wound, News.Sky.com reported.

Police call the incidents "strange offenses" and are unclear of the motive.

According to News.Sky.com, police presence has increased in Birmingham to reassure visitors. 

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