The Reagan administration's counterterrorism programs may lead to the killing of innocent bystanders on occasion during operations responding to terrorist acts, two top administration officials said yesterday.

Fred C. Ikle, undersecretary of defense for policy, and Robert B. Oakley, director of the State Department's office for counterterrorism, told a Senate hearing that administration policy-makers try to minimize the risks to bystanders as they weigh how to attack growing worldwide terrorism.

Sen. Thomas F. Eagleton (D-Mo.) raised the issue in pressing Ikle for an explanation of whether the administration condoned a car bombing in Beirut in March that killed more than 80 people and that, according to a Washington Post report, was the work of a group hired by Lebanese working with the CIA.

Eagleton said he could not understand Reagan's policy because at different times, Secretary of State George P. Shultz has said innocent lives would be lost in responding to terrorists, while Reagan and Vice President Bush have said they did not want to endanger innocent lives.

"Can you help me on this?" Eagleton asked Ikle. "Can you help the country?" Referring to the "boo-boo in Beirut," Eagleton said he wanted to speak out about the use of U.S. antiterrorist proxies before he was "silenced" by knowledge of classified material from a CIA briefing on the subject scheduled later in the day at the Senate Select Committee on Intelligence.

Ikle said he knew nothing of the Beirut bombing. He added, "There is a potential for the loss of innocent life in Philadelphia or Beirut," an apparent reference to the Philadelphia police shootout with the militant MOVE group.

Oakley said later that "it is completely misleading and unfair to imply the action in Beirut was the responsibility of the U.S. government. There's just no justification for that." But he also said "there are going to be times when innocent life is going to be taken."

Sen. Jeremiah Denton (R-Ala.), a former Navy admiral and Vietnam prisoner of war who chaired the joint hearing of the Senate Judiciary subcommittee on terrorism and the Foreign Relations Committee, noted that the rules of warfare do not consider it a crime to kill civilians in pursuit of military targets.

Sen. Joseph R. Biden Jr. (D-Del.) broke in to say that while the rules of war are clear, "we're deciding now whether counterterrorism incidents rise to the level of warfare or whether we treat them as police actions."

". . . We are trying to find out, have we already made a judgment? Have we elevated counterterrorism to a state of war? . . . "