Prince George's County officials joined apartheid protesters outside the South African Embassy yesterday, pledging support for the Free South Africa Movement and saying the county is making sure it has no direct or indirect investments in that country.

Two demonstrators, including syndicated journalist Ethel Payne, 73, were arrested earlier in the afternoon after they entered the embassy on the pretext of seeking information and then refused to leave.

Prince George's County officials at yesterday's embassy demonstration were led by Rep. Steny Hoyer (D-Md.), who said a cross-section of county citizens had joined the protest because they believe "the policies of apartheid are immoral and ought to be immediately abandoned."

Marching in the cold rain, the bipartisan contingent of about 40 persons included County Executive Parris Glendening; Maryland Secretary of State Lorraine Sheehan; members of the county's delegation to the General Assembly, including a majority of its state senators; county council members, and other Democratic and Republican activists in Prince George's.

Glendening said the county has no direct investments in South Africa and is checking now with banks in New York, where the county has some pension funds, to make sure those institutions do not have South African investments.

A sponsor of the Gray Amendment, which would impose economic sanctions against South Africa, Hoyer predicted during yesterday's embassy protest that there will be "a lot more enthusiasm" for the measure in Congress this year. The legislation was approved by the House last session but killed in the Senate.

Randall Robinson, who heads the TransAfrica foreign policy lobbying group and who is a key organizer of the embassy protests, called yesterday's arrests a departure from the demonstrations' weekday afternoon routine and said apartheid protesters are going to be "a good deal less predictable" in the weeks ahead.

Robinson said future arrests may not always occur in the same manner or at the same time, 4:30 p.m., as they have in the past. Such a new tactic would further complicate operations at the embassy, which has come to expect visits by the anti-apartheid "messengers" in the late afternoon.

A spokesman for the Secret Service, which was called in to arrest the protesters after they entered the embassy at 2:45 p.m., said Payne, a columnist with the Afro-American newspapers, and Sylvia Hill, 44, a criminal justice professor at the University of the District of Columbia, were charged with failure to quit and unlawful entry, a misdemeanor violation of the D.C. Code.

The two women spent about an hour in the embassy, pressing their demands that South Africa release all political prisoners and begin discussions on a fair constitutional government in the white-ruled, majority-black nation. It was the first time any of the antiapartheid demonstrators had gotten inside the embassy since the protest was launched Nov. 21 with the embassy sit-in arrests of three Free South Africa Movement leaders.

In announcing a change in tactics, Robinson said two people, California Assembly member Maxine Waters and the Rev. Hartford Brookins, had entered the lobby of the South African consulate in Los Angeles yesterday with sleeping bags and intended to "camp out" in protest against apartheid.