The Fairfax County prosecutor said yesterday that he will not apologize for a comment that has sparked demonstrations in Pakistan and prompted the State Department to express its regret to Pakistani officials.

Commonwealth's Attorney Robert F. Horan Jr., who is prosecuting the capital murder case of Mir Aimal Kansi, was interviewed by WTTG-TV (Channel 5) June 23 about the $2 million reward the United States offered for Kansi's capture after he fled to his native Pakistan. Kansi is accused of killing two people and wounding three others outside the CIA's Langley headquarters in 1993.

"I am not sure a quarter of a million {dollars} wouldn't have done the same thing because it is in a very rural, backward area of western Pakistan and southern Afghanistan," Horan said during the broadcast. "I am sure there are people over there who would turn in their mother for $20,000, let alone $2 million."

A group of 50 Islamic activists demonstrated outside a mosque Monday in Lahore and demanded an official apology from Washington, the Associated Press reported. That protest followed one held Sunday in Karachi in which hundreds of members of a right-wing political group burned an effigy of President Clinton and a U.S. flag, and a Saturday demonstration in which more than 50 people gathered outside the American Center in Lahore and threw stones at the building.

Horan said yesterday that his comments had been directed at the group that helped protect Kansi while he was hiding in Pakistan and Afghanistan -- not at the population at large. He said that he intends to write a letter of explanation to Prime Minister Nawaz Sharif, who told the Pakistani media that Horan's comments were "totally uncivilized, devoid of human values." But, Horan said, "you don't apologize for what you didn't do." He added: "I am a prosecutor, not a diplomat."

An official at the State Department said it had expressed regret to the Embassy of Pakistan, which has formally objected to Horan's comments.

"We regret the television interview remarks by {Horan}, which were insensitive and offensive to Pakistanis," said spokeswoman Stephanie Eicher. "We have urged Horan to discuss the matter with the Pakistan Embassy."

The Kansi case already had spawned hard feelings in Pakistan. Many groups were furious that FBI agents captured Kansi and brought him to the United States in June without an extradition hearing.

Hamidullah Kansi, 43, Kansi's oldest brother, who attended a hearing in the case yesterday in Fairfax Circuit Court, said he also found Horan's comments offensive: "I think it was a very insulting statement to the whole nation."

Security at yesterday's hearing was tight, with sharpshooters posted on the courthouse roof and a metal detector outside the courtroom. County and police officials have privately raised concerns about a potential terrorist attack, and sources said the county has hired a Centreville security firm to advise officials about possible countermeasures.

At the hearing, the defense won a partial victory on its motion asking Horan to turn over any evidence that could help prove Kansi is not guilty.

Assistant Public Defender Crystal A. Meleen argued that Horan should be required to disclose criminal records of witnesses, whether any FBI technicians who tested the evidence were mentioned in recent critical reports about the FBI laboratory, and the names of anyone whose fingerprints were compared against those at the crime scene.

She also asked for witness descriptions of the CIA gunman that do not match Kansi's appearance, such as varied height estimates and clothing descriptions.

Judge J. Howe Brown Jr. ordered the prosecution to turn over the contradictory descriptions. "The difference between a white jacket and trench coat is substantial," Brown said. Brown denied two other defense motions: one asking him to declare Virginia's death penalty statute unconstitutional and another requesting a "bill of particulars," which would have required Horan to tell the defense what evidence he plans to use to prove that Kansi is guilty of capital murder and deserves to die.