BEIRUT, NOV. 14 -- A ribboned chocolate box carried by a drowsy woman blew up near the main elevators of the American University Hospital at the peak of visiting hours today, killing the woman and six other persons and wounding 31, police said.

The woman, in her late thirties, sat down on a bench in the ground-floor lobby with the box in her lap after going through a routine security check, a police officer said.

"She appeared sedated and edgy," a witness said.

Within moments, the blast devastated the waiting area, leaving the shiny green and yellow marble walls splattered with blood and the once spotless floor a bloody scene of charred bodies and moaning victims. White and purple carnations brought for patients littered the floor.

{In Washington, the State Department said there was no indication that Americans were among the victims, The Associated Press reported. In a statement, it branded the bombing "particularly despicable and utterly heartless" because it brought "terror into a place of healing."}

The explosion inside the Syrian-guarded hospital was the second this week in a major public building. No one has taken responsibility for either blast.

Last Wednesday, explosives in a suitcase carried by a woman ripped through the entrance of Beirut International Airport, also guarded by Syrian troops, sent to the western half of the Lebanese capital in February to maintain security. The airport bomb killed five persons, including the woman carrying it, and wounded 73 Lebanese and Syrians.

The bombings in west Beirut are interpreted here as blows to Syrian authority. Druze politician Marwan Hamadeh expressed his outrage at the first such attack inside a hospital as "part of the unending cycle of violence, the perpetrators of which are always one and the same."

A security official said, "The blasts are aimed at killling as many people as possible in places under Syrian control in order to challenge their role." He added, "We do not rule out the possibility that drugged women are being used to carry out these missions."

In the hospital lobby, a soot-blackened marble sign read: "A gift from the people of the United States of America to the people of Lebanon and the Middle East." The 142-bed hospital is one of the few major U.S.-funded institutions still operating in Moslem west Beirut.

Syrian troops manning barricades around the hospital blocked access to hysterical people who came to inquire about patients and workers trapped inside. Explosives experts said the blast was caused by 1.75 pounds of TNT linked to a detonating device wrapped in a thin layer of Swiss chocolate.

His eyes red and brimming with tears, Khalil Raishouni sat on the edge of a low wall near the hospital.

"I came to see my nephew. We lost him. He was an only son, Nazih Kamouriyeh . . . . I just heard his name on the radio," the elderly man sobbed. Kamouriyeh, 21, a mechanic and an award-winning body builder, was the only provider for his two sisters and ailing mother. His father was killed five years ago by a stray bullet during one of Beirut's many street fights.

Authorities said four of today's dead were men, and the three other bodies were so mutilated that they could not be identified.

Dr. Ziad Haidar, an internist on duty at the hospital's emergency room, said, "The wounded with small lacerations were the first to arrive because they could get up and walk. But they were rapidly pushed aside to deal with the more serious and traumatic cases."

Reflecting on his own reaction to the blast, Haidar observed, "When you first hear the sound, the screams and you smell the blood, you are always shocked. But when you rationalize, you can almost expect such things to happen. It is in the logic of the Lebanese war that such acts will always occur to keep the Lebanese divided.

"Last week you had a joint strike by Moslems and Christians protesting the same economic conditions, making the same demands for security and an end to the war. This {blast} was as if to remind them that they are not allowed to be united," he added.

Another physician who had come to identify his cousin's body at the morgue was more indignant.

"Such bombs should be meant for politicians and fighters and should not target innocent, helpless people in a hospital," said Dr. Sami Raishouni.

In the last three years, the American University of Beirut, with which the hospital is affiliated, has been subjected to a wave of attacks, killings and kidnapings. The university's president, Malcolm Kerr, was killed Jan. 8, 1984, by a gunman who came up to his office on the sprawling seafront campus.

An English political science professor, John Leigh Douglas, and an American librarian, Peter Kilburn, were kidnaped and later found slain two days after the U.S. raid on Libya in April 1986.

David Jacobsen of Huntington Beach, Calif., was the hospital's last American director. He was kidnaped in west Beirut by Shiite Moslem extremists on May 28, 1985, and released Nov. 2, 1986, after 18 months in captivity.