State Sen. Clarence M. Mitchell III, who two months ago delayed an announcement on his political plans following disclosures that he was being investigated by federal authorities, said today he will seek the seat in Congress being vacated by his uncle, Parren Mitchell.

Mitchell, 45, was joined by his family, including his uncle, at a noon announcement downtown. He refused to respond to questions about the continuing investigation. Sources have the probe concerns possible perjury and obstruction of justice.

Parren Mitchell, who is running for lieutenant governor on a Democratic ticket with Maryland Attorney General Stephen H. Sachs, endorsed his nephew as a band played "You'll Never Walk Alone."

"There was some question in some ignorant people's minds about who I would endorse," said Parren Mitchell. "There was never any question in this man's mind about who he would endorse. There's only one. Clarence Mitchell."

Baltimore City Council member Michael Mitchell filed last week to run for his brother's state Senate seat.

"This is a family of freedom fighters," said Juanita Jackson Mitchell, who is Michael and Clarence's mother and the widow of NAACP activist Clarence Mitchell Jr. "We are not going to stop. Nothing is going to stop us until freedom is won. Vote for Clarence Mitchell. Vote for Parren Mitchell for lieutenant governor and for Michael Mitchell for Senate."

Among the observers in the crowd today was A. Dwight Pettit, the Baltimore attorney who is among several others also seeking the 7th Congressional District seat. He said he came because he was invited. Other Democratic candidates for the seat are Sandra Stewart, A. Dwight Pettit, Baltimore City Council member Kweisi Mfume, Augustus Adair, state Del. Wendell H. Phillips.

St. George Crosse is seeking the Republican nomination.

Del. Nathaniel Oaks (D-Baltimore), who is supporting Phillips, said he wandered into the gathering by accident. After watching the speeches and enthusiasm for some minutes, Oaks walked away muttering, "Rough man, rough."

Mitchell, in response to questions about the continuing federal investigation, said: "I'm concentrating on the campaign and that's my total area of concentration."

Sources close to the probe have said that it is focusing on whether Mitchell arranged fabrication of financial documents to support allegedly false testimony he gave last year to a federal grand jury investigating whether he has business ties to a major Baltimore heroin dealer. But Mitchell said the whole story has not yet been told.

"You remember when a newspaper in this town dubbed me the 'king of the streets,' " Mitchell said. "That newspaper is not in business anymore, but I'm still in the streets."

"An impartial review of the facts will show that I have done nothing wrong," he added