An apparent assassination attempt against President Raul Alfonsin, a rash of bombings at political party headquarters and several unsolved kidnapings have raised serious questions about the government's efforts to curb political violence and rein in renegade sectors of the military intelligence services.

The discovery of a powerful bomb at a military base in Cordoba Province where Alfonsin was watching military exercises last month increased the unease here over the growing violence.

There were nine bombing attacks against local headquarters of the ruling Radical Civic Union last month, and a powerful blast wrecked the offices of national Peronist party leader Vicente Saadi. In addition, there has been a growing aura of scandal over the government's handling of the kidnaping of businessman Osvaldo Sivak, missing since last July.

For Alfonsin, the wave of unrest marks a challenge to his ability to dominate the intelligence services. The kidnapings are believed to be a continuation of the habits acquired by intelligence personnel during the last military regime, when scores of businessmen were abducted and held for ransom by agents, who often posed as leftist guerrillas.

The violence also comes amid Alfonsin's continuing efforts to prosecute military and police personnel who committed human rights violations during the "dirty war" against leftist insurgents and other dissidents.

The current bombing campaign, like several others that have marred Argentina's return to democracy since 1983, has been linked by government officials and others to both active and retired security-force personnel unwilling to accept the new political system. Although these are widely believed to be small groups with virtually no popular support, their acts of intimidation have at times succeeded in creating an atmosphere of unrest.

On May 22, Interior Minister Antonio Troccoli was called before Congress to answer questions about the government's handling of the Sivak case. According to reports published in the press here, at one point the government, stymied in its efforts to solve the kidnapings, sought the aid of three military and state intelligence agents, who later were accused of pocketing thousands of dollars in ransom money.

During his testimony, Troccoli said the police had never abandoned their search for Sivak and that the investigation had never been handed over to anyone else. The assertion caused Sivak's brother, who was watching the proceedings from the gallery, to jump up and cry, "Don't lie, don't lie." The hearing was adjourned.

The Sivak case is one of several recent kidnapings in which government and police sources say they suspect current or former security personnel of having a role. Last month the son of Cordoba businessman and one-time lobbyist Raul Pinero Pacheco was abducted for ransom, and family members told the press that in telephone conversations his captors used jargon characteristic of the security forces.

The unsolved kidnapings and the fact that no one was apprehended in the bombing attacks have led to calls for a radical restructuring of the state intelligence services, which number more than 25. Critics say these are both inefficient and frequently at odds with the needs of the country's 30-month-old democracy.

The growing concern here was reflected in a series of paid advertisements in local newspapers entitled, "Each of us could be Sivak."

Endorsed by such diverse figures as former military president Alejandro Lanusse, newspaper publisher and former political prisoner Jacobo Timerman, human rights leader Emilio Mignone and soccer coach Cesar Luis Menotti, the ad referred to Greater Buenos Aires as a no-man's land and added: "We all know that the Mafia-like terrorist state apparatus still exists, as much within as outside the security forces."

Critics of the government have pointed out that an attempt to murder former president Isabel Peron and several hundred other people by planting a bomb on the airplane in which she was riding in 1984, a similar try against Sandro Pertini, then Italian president, and a rash of bombing attacks in October were never satisfactorily cleared up.

"The government's record in this vital field is dismal," editorialized the English-language Buenos Aires Herald on May 21. ". . . It simply cannot afford to let the investigation of what must be treated as a serious attempt to murder President Alfonsin take the same course, with statements to the effect that the perpetrators will soon be caught getting less and less frequent until the whole affair is forgotten."

On Thursday, Army Chief of Staff Gen. Hector Rios Erenu acknowledged that a "cleanup is taking place" inside the military as a result of the Cordoba incident.

Some observers say the government's dilemma is best illustrated by what happened after last October's bombings, which resulted in the imposition of a state of siege. A dozen military men and civilians were arrested and accused of taking part in a campaign to undermine the government.

The government, not trusting existing intelligence agencies, asked sources within the telephone company to assist in the investigation, according to federal court and intelligence sources. It collected a substantial body of evidence, which officials said privately included tapes of telephoned bomb threats to schools emanating from the 601 Intelligence Battalion. This evidence could not be used in court, however, because it came from unofficial sources, and the suspects were released.

The inability of the administration to make the charges stick left it open to criticism that the crackdown was designed to boost its standing in November parliamentary elections.

According to several published reports, Alfonsin decided to go to the Cordoba Army base last month despite warnings about animosity that his rights policies had caused among middle-level officers there. The headquarters of the powerful 3rd Army Corps in Cordoba was the site of some of the most bloody repression during the repression of leftist guerrillas and suspected sympathizers in the late 1970s.