The Washington Lawyers' Committee for Civil Rights Under the Law announced yesterday that it will provide free legal assistance to victims of racial and religious harassment and will develop "model legislation" for metropolitan jurisdictions to cover such incidents.

The lawyers' committee, which has been active in prosecuting racial discrimination cases, said it is starting this program because of the increased incidents of cross-burnings, vandalism and personal attacks directed against minorities and certain religious groups in the Washington area.

"We will encourage victims to prosecute. In the past, a lot of this problem was kept in the closet," said Roderic V.O. Boggs, committee director.

At a press conference yesterday, committee lawyers said that in Maryland, there were more than 247 incidents of violence stemming from racial and religious hate during the first six months of this year, compared with 347 such incidents during all of 1981.

The Montgomery County Human Relations Commission reported that incidents involving racial or religious harassment rose from 98 in 1981 to 156 between January and November of this year. Montgomery has had the highest number of such incidents in the state.

Prince George's reported an increase from 16 incidents in 1977 to 45 this year.

Statistics on violent incidents stemming from racial or religious hate in Washington and the Virginia suburbs were not available yesterday. The most recent report by the Anti-Defamation League of B'nai B'rith showed anti-Semitic incidents nationally increasing from 377 in 1980 to 974 in 1981.

Committee lawyers said area jurisdictions should consider increasing the civil penalties for committing such violence, as Montgomery County did earlier this month. Montgomery has also established a $50,000 tipsters fund to aid in the arrest of people responsible for the incidents.

The Prince George's County Council recently proposed tougher penalties for defacing buildings and the wearing of Ku Klux Klan-style masks.