Italy, involved in a major crackdown on suspect Libyan activities here, today expelled another five Libyans who were found to be running a publishing company outside Rome without authorization.

The new round of expulsions, which brought to 24 the number of Libyans ordered to leave the country in the past month, came as Italian magistrates investigating the attack on Rome's Leonardo da Vinci International Airport on Dec. 27 were reported to be focusing on the possible involvement of some Syrians.

Sources close to the investigation being conducted by public prosecutor Domenico Sica and investigating magistrate Rosario Priore today denied reports that they had issued arrest warrants for 20 Syrians allegedly involved in the airport attack. But they made it clear that a "list of suspected accomplices" of the four Palestinians who carried out the attack is believed by investigators to include some Syrians, although probably not as many as 20.

The assault on Rome's airport, which resulted in the deaths of 17 persons, was initially viewed here as having been supported by Libya. As a result, Italy began the crackdown on Libya and its vast commercial and propaganda activities here.

The disclosure that Syria may have been involved in the airport massacre has come as something of a surprise here as the crackdown on Libya gathered steam. It includes a major government investigation of Libyan investments and actions here and an extensive review of the legal status of the estimated 3,500 Libyans living in Italy.

The five Libyans expelled today all worked for a Libyan-owned publishing company known as Star Photolito that specialized in publishing political books for Arabs living in Europe. The company's president, Abdulmagid Adoushwesha, 48, and four of his employes were given seven days to leave Italy because they were in the country with tourist visas instead of required working papers.

While the government focuses its attention on Libya, the judicial investigators looking into the airport attack are increasingly intrigued by the Syrian connection behind the four Palestinians directly involved, only one of whom survived the shoot-out with airport security agents.

The apparent Syrian connection goes back as far as January when the surviving terrorist, Mohammed Sarham, told his questioners that he and his fellow terrorists, along with three others who simultaneously attacked the international airport in Vienna where three other persons died, had been trained in camps in the Syrian-controlled Bekaa Valley of Lebanon. He reportedly said the terrorists had then gone to Damascus, the Syrian capital, to catch a flight to Belgrade, Yugoslavia, from where they made their way to Italy by train.

Recently, sources close to the investigation said this week, Sarham has claimed a greater Syrian involvement by telling investigators the names of those who allegedly trained and directed the terrorists. An unspecified number of those named are Syrians, according to the judicial sources, although most appear to be Palestinians or Lebanese.

It is a list of those names of "suspected accomplices" that has now given rise to reports -- officially denied -- that warrants for the arrest of 20 Syrians were prepared by the judges. Although the judges refused to comment on the reports today, their aides privately told all callers that no arrest warrants had been issued, even though some might be in the coming days.

But the sources said that despite all speculation, the investigation had yet to establish a "direct responsibility" of Syria in the airport assaults. These sources said the Syrian involvement appeared to be an organizing role in the attacks, which were carried out by terrorists loyal to the renegade Palestinian Sabri Banna, better known as Abu Nidal. The sources said there were still no links between the alleged role of some Syrians and the Syrian government.

Some reports have said that Gen. Mohammed Khouli, chief of the Syrian Air Force's intelligence organization and one of President Haffez Assad's closest collaborators, has been implicated.

But sources close to the investigation and senior Italian officials have denied that there is any proof that would directly implicate the Syrian government.