New York City Police Commissioner Raymond Kelly is stepping up security in East Harlem after a string of violent robberies targeting people of Asian descent.

Police say a man has attacked seven people of Asian descent in the neighborhood since Jan. 17. Police say the suspect follows his victims into elevators and assaults them repeatedly by punching them in the face and head before robbing them.

City leaders in the Asian community held a rally Saturday to condemn the violence.

The NYPD says officers from the city's hate crime task force and officers fluent in Mandarin and Cantonese have also been assigned to the neighborhood.