Despite dozens of raids and the arrest of more than 1,100 persons during a state of siege, the government of Gen. Augusto Pinochet has failed to show gains against terrorist groups that are the declared object of the crackdown, according to human rights groups and other informed sources here.

Pinochet cited an upsurge in political violence, including several fatal bombing attacks on police, as justification for ordering the state of siege Nov. 6. Since then, official spokesmen consistently have described such measures as searches of political party and union headquarters, massive raids on poor neighborhoods by troops and nearly daily arrests of other activists as part of an antiterrorist campaign.

However, human rights groups and sources with access to official information here said authorities so far have shown little success in capturing or immobilizing terrorists since the state of siege was implemented. According to the Chilean human rights commission, 1,120 persons have been arrested by police and troops in the past two weeks, and 467 have been sentenced to internal exile, but none has been charged under laws against terrorism.

"Not a single one of the 400 people they have relegated to internal exile has links to terrorism," said one prominent human rights lawyer, who asked not to be named for reasons of "personal security." "If the object is really to combat terrorism, then they haven't achieved anything."

Interior minister Sergio Onofre Jarpa reported yesterday that the state of siege had been effective because "terrorist attacks have very clearly decreased." However, other sources here indicated that the government has failed to report publicly or acknowledge about 40 bombing attacks carried out during the past two weeks, to foster the image of internal stability.

Today, an official communique acknowledged a car bomb that exploded outside Valparaiso's police station early this morning, slightly injuring two policemen.

The bombings, mostly directed at public property, occurred on seven of the first nine nights under the state of siege, which was accompanied by a curfew in Santiago and other major cities, sources said. Other blasts occurred Monday night. Three persons were injured by one bomb in the mining center of Rancagua last week.

Pinochet's government, which has shut down most of the opposition press and applied strict censorship to remaining media, suppressed the one report on bombings made since the state of siege by the government news agency Orbe. Questioned about bomb reports, an official of the government information agency said that there was "no official information" on the subject.

Authorities have reported only one concrete case of charges brought against alleged terrorists. Six persons arrested in one secret police operation in the poor neighborhood of La Legua have been transferred to a military court and accused of involvement in the bombing of a police barracks in Santiago that killed two persons earlier this month.

In addition, government officials have announced the confiscation of arms during two military raids on poor neighborhoods as well as the arrests of about 90 persons with "subversive connections."

Human rights lawyers investigating the cases maintain they have strong evidence that the suspects charged with the police barracks bombing were not involved in the attack. One of the persons arrested, these sources said, was in a neighborhood church visiting a priest when the incident occurred.

Critics also point out that the government has not provided any public accounting of the arms reportedly confiscated and the persons held for "subversive connections" have not been charged with crimes. "Subversive connections can mean anything, like having a pamphlet in your house," said a human rights activist.

Human rights groups and most opposition leaders do not dispute the government's claim that leftist terrorist groups are active and that the number of violent incidents has increased markedly this year. More than 400 bombings were reported in the first 10 months, and about 20 policemen have been killed in explosions or shootings.

However, opponents of the government maintain that the terrorism has been used by Pinochet as an excuse to attack all opposition. In addition, these groups charge that the government is responsible for at least some of the terrorist incidents, including several major bombings.

The principal armed groups known to be operating in Chile are the Revolutionary Leftist Movement, a militant organization formed in the 1960s with ties to Cuba; the leftist Manuel Rodriguez Patriotic Front, which appeared this year; and the right-wing Anticommunist Chilean Action.

The Revolutionary Leftist Movement has claimed responsibility for several of the most sensational terrorist attacks in recent years, including the August 1983 assassination of Army Gen. Carol Urzua, the military superintendent of Santiago.

However, the group has lost dozens of militants to operations by security forces in the last several years, and knowledgeable sources say its military activities now appear to be limited, in part because members believe their ranks have been thoroughly infiltrated by Chile's secret police.

In contrast, the two newer groups have alarmed many observers with both their growing activities and apparent ties to powerful institutions on the left and right.

Informed activists in leftist political parties say the Rodriguez Front, which has claimed a number of bombings, is connected to the Chilean Communist Party, if not controlled by it. Communist spokesmen deny the link, but party youth groups openly carry out propaganda tasks for the front -- such as putting up posters and stickers in universities.

Chilean Action, in turn, was linked to the armed forces last month after a bomb exploded in a church in the southernmost city of Punta Arenas, killing an Army lieutenant assigned to intelligence work who apparently had been carrying the explosive. Chilean Action pamphlets were found at the site of the blast.

Other cases this year have increased suspicion about military involvement in cases of violence. In May, a woman was killed by a bomb planted near an electrical tower hours after she and her husband allegedly were abducted by secret police. In September, an Army officer and operative of the secret police was shot in the city of Copiapo when, dressed as a civilian, he allegedly led attacks on police during a violent student demonstration.

"For people of the government, all terrorism comes from the left and the Communists," said the human rights lawyer. "In contrast, for people of the opposition, all the terrorism is being staged by the government. The truth is that it is coming from both sides, and so no one really knows anymore who is responsible."