Prince George's County police arrested an Oxon Hill man yesterday and charged him with several rapes that occurred over the last two months in Oxon Hill and Bladensburg.

Michael Walker, 19, of the 2200 block of Alice Avenue, was charged with four counts of first-degree rape, a count of attempted first-degree rape and a residential armed robbery, authorities said. Walker was being held without bond last night at the Prince George's County jail.

Police said they plan to present additional charges against Walker to a county grand jury.

In most of the cases, women were approached from behind in the late-night or pre-dawn hours by a man who threatened them with a knife, police said. One of the women was accosted in a parking lot near her apartment in the 5800 block of Annapolis Road in Bladensburg; two women were stopped while they were walking near St. Barnabas Road and Interstate 95 in Oxon Hill; and another woman was accosted when she stopped to use the telephone at a gas station in the 5600 block of St. Barnabas Road, police said.

In the only rape that occurred during daylight hours, an 18-year-old was accosted shortly after 10 a.m. in the 5500 block of 57th Avenue in Bladensburg and forced into the underbrush of a vacant lot, police said.

The first rapes occurred on May 10 and May 20 in Bladensburg; the rest of the sexual assaults occurred in Oxon Hill, police said.

Police, who said Walker matched a description of the suspect, picked him up for questioning at his home late Tuesday. Police sources said Walker lived in Bladensburg before moving to the Alice Avenue address in June.