Swedish police are warning residents and tourists to be on alert for a gang of thieves who pickpocket valuables while hugging their victims.

The gang, which could include up to four men, have robbed more than 20 people in Stockholm, The Local reported Wednesday.

"Even men have fallen victim," said Gunnar Thun of Stockholm police. "But in those cases it's more of an embrace or a pat on the back."

Police said victims have reported one thief usually approaches and hugs the victim without any greeting, sometimes even lifting them off the ground. Meanwhile, a second thief takes the opportunity to steal valuables from the victim, mostly wallets and mobile phones.

The attacks have happened mostly at night and usually target young girls.