Attorney General Edwin Meese has suffered a serious blow from the resignations of two top Justice Department officials and four aides said to have quit to avoid spilling "blood on the floor" because of the legal and ethical questions surrounding him.

The resignations, which left a gaping hole in senior department leadership, have prompted increased calls for Meese to step aside and caused growing concern in Congress that the department cannot fulfill its mandate as the key government law enforcement agency.Deputy Attorney General Arnold Burns, the No. 2 official under Meese, and Assistant Attorney General William Weld, chief of the department's criminal division, both submitted their resignations Tuesday to President Reagan but refused to disclose their reasons publicly. Four other top aides, including two career attorneys, also resigned, officials said.

Speculation abounded that another ranking department official was preparing to quit, possibly Solicitor General Charles Fried, but Fried said Tuesday he had no such plans immediately.

At a brief, final staff meeting, Weld told lawyers in the criminal division that his decision had to do with Meese's ties to attorney E. Robert Wallach and the departmental tension caused by the continuing criminal investigation of the attorney general by independent prosecutor James McKay.

"Rather than have 50 fights and blood on the floor," Weld concluded, "it was better to leave."

Wallach, the attorney general's longtime friend and lawyer, has been indicted in New York on charges of attempting to influence Meese in the Wedtech Corp. scandal and is a central figure in the current probe of Meese's connection to a $1 billion Iraqi pipeline venture.

According to two participants, Weld won a standing ovation before leaving the department for a final time. John Keeney, a career prosecutor, reportedly was named acting assistant attorney general.

It was understood that Burns and Weld, having decided upon what one source described as "a Meese or us" ultimatum, approached White House chief of staff Howard Baker in recent days, hoping to submit resignations directly to him.

After being told to follow bureaucratic routine by resigning to Meese, the two confronted Baker again Tuesday morning at his home, where he agreed to accept their letters but gave them to the president only after they stunned Meese personally with their news.

Reagan, who consistently has backed his old friend and adviser, found himself reiterating that support once again.

"The president has full confidence in the attorney general," spokesman Marlin Fitzwater said. "The Justice Department has been functioning just fine."

Justice Department spokesman Terry Eastland said Burns and Weld planned to return to the private sector, though neither had a job offer, and he said Meese would move promptly to replace them.

Though Weld said he and Burns had decided not to disclose their reasoning publicly, department sources confirmed the move was sparked by dissatisfaction with Meese and how continuing legal and ethical questions have hindered his ability to run the department.

Burns has been forced to fill in for Meese on several issues the attorney general has excused himself from, including the department's recent challenge to the independent counsel law under which prosecutor McKay was appointed.

Meese, called frequently to testify before the grand jury in the Iran-Contra case of independent prosecutor Lawrence Walsh, is under investigation by McKay for his role in the Iraqi pipeline venture as well as in the scandal centered on Wedtech, the now-bankrupt New York City defense contractor. McKay's office denied Tuesday that any new information had been forwarded in the matters.