Under the glare of television cameras in a courtroom in the Philippines, someone yelled that the building was on fire. The judge hastily adjourned the session until firefighters extinguished an electrical blaze.

"Now there's going to be another charge against us," joked Jose Burgos Jr., editor and publisher of the opposition tabloid newspaper We Forum and charged with conspiring with a now-defunct urban guerrilla group of arsonists to subvert and topple the government.

The incident livened up what lawyers said was one of the tamer sessions of the nine-week-old case, in which 15 of Burgos' staffers and contributors also have been charged.

Earlier, the proceedings had to be adjourned when a defense lawyer, gesturing grandly, knocked off a colleague's toupee. On a separate occasion the judge fined another defense lawyer $22 for contempt of court when he laughed out loud at a prosecutor's remarks.

With spectators and reporters jamming into the small courtroom, the trial has taken on something of a circus atmosphere. But aside from its entertainment value, lawyers say, the trial has serious implications that keep it a focus of keen public interest.

Beyond the immediate charges--for which the maximum penalty is death--defense lawyers see the proceedings as part of a trial of press freedom in the Philippines, the latest turn of the screw in a six-month-old campaign against dissidents. The arrests were ordered by Marcos after the paper published a series questioning whether he merited all of the World War II medals that he reportedly won.

The case and related developments also demonstrate that although Marcos lifted martial law two years ago last month, it remains substantially in effect for practical purposes through a series of presidential decrees still being used to arrest and detain dissidents.

According to Marcos' opponents, the crackdown started shortly before Marcos made a state visit to the United States in September, ending a period of some liberalization after martial law was lifted in January 1981.

Dissident labor leaders were rounded up and put on trial, stemming--at least for the time being--a movement toward political protest strikes. Next the government launched a campaign against radical elements in the influential Roman Catholic Church, a powerful institution in this predominately Catholic country.

Then in December the authorities closed We Forum, bringing the subversion charges and sponsoring a separate libel case against Burgos and the author of the offending article. At the same time, six women journalists were summoned to a series of interrogations by the president's national intelligence board that they said were aimed at intimidating them.

Two weeks after closing We Forum, Marcos threatened to take action against the progovernment Bulletin Today newspaper if it did not publish his denial of a letter it printed charging that political prisoners had been tortured. Early this month the military followed up by threatening to file charges of "scurrilous libel" against Panorama, the Sunday magazine of Bulletin Today. The Army has since backed off slightly by announcing the dissolution of the national intelligence board committee that had been interrogating the women journalists, who sought an injunction from the Philippine Supreme Court.

Most of Manila's major newspapers and television stations, including Bulletin Today, are owned by Marcos' friends and loyally exercise a "self-censorship" that cuts out critical reporting. But some reporters and columnists still manage to air critical views, and authorities often ignore opposition papers with small circulations in Manila and the provinces.

While there is some disagreement among diplomatic observers on opposition leaders' claims that the crackdowns on labor, radical clergy and the press amount to a coordinated campaign of political repression, there is little doubt that a trend toward more press freedom has been arrested.

"What I'm sure of is that the government has been very successful in silencing We Forum and instilling fear in people," publisher Burgos said. "The main concern is to stifle dissent, to keep people from complaining."

"At the moment there is no freedom of the press," said Joker P. Arroyo, one of a battery of defense lawyers in the case.

He noted that although the Philippines has a press freedom law that is a "carbon copy" of the First Amendment of the U.S. Constitution, Marcos has the power, under a Sept. 12, 1980, decree issued during martial law, to close "subversive publications or other media of mass communications," order "preventive detention," ban entertainment or exhibitions deemed detrimental to national interests and control admissions to educational institutions. Arroyo said Marcos has not yet invoked this decree but has used other means to stifle the press.

In the subversion case against Burgos and his codefendants, defense lawyers charge, the government manipulated another case to get the "evidence" it needed. They said that on Dec. 13--hours before the Burgos group was to be arraigned--two defendants in the three-year-old case of the accused Light-a-Fire movement arsonists suddenly turned state's witness and implicated Burgos.

The following day the major Manila newspapers all carried identical stories linking the accused in the Light-a-Fire and We Forum cases as members of one conspiracy.

Outraged by what they called the two defendants' "newly fabricated and fantastic story," all four defense lawyers withdrew from the Light-a-Fire case, which continues to be tried by a military court despite the lifting of martial law.

"Let this case continue then to be tried by soldiers alone, who may never understand why this nation is being riven apart by the rampant militarization of almost everything, including the trial of purely civilian defendants, by a purely military tribunal, a purely military prosecution panel, and now, apparently, a purely military defense panel as well," the lawyers said in a Jan. 10 joint statement.

"In the end, only Mr. Marcos will decide anyway the fate of the accused here," it concluded. "Let that be expedited now by having the military have its way."

Despite the twist, said Rene Saguisag, who had been a defense lawyer in both the We Forum and Light-a-Fire cases, "nobody takes seriously the charge that they Burgos and his codefendants were out to overthrow the government." He noted that the editor-publisher and nine others who are actually on trial--the rest are out of the country or at large--were held for only a week and did not have to post bail.

One, former publisher Joaquin Roces, 69, whose newspaper was closed when Marcos declared martial law, told the judge he had no interest in presenting a defense and asked if he could go home. The judge let him.

"The intent was just to cripple Burgos and close down the paper," said Saguisag.

He and other opposition figures believe the crackdown on dissenters has intensified as a result of Marcos' visit to the United States, in which he was warmly welcomed by President Reagan.

"Marcos went to the United States and didn't get the sort of rubbishing he thought he might get on human rights," a western diplomat said. "He returned from Washington pretty confident both of himself and the way he is viewed in the U.S."

Marcos "was probably feeling in the last quarter that it was time to make a show of strength again," this diplomat said. "The press was becoming more outspoken, and We Forum offered the opportunity he wanted."

According to former Philippine president Diosdado Macapagal, a deeper cause for the crackdown was "an increased threat to stability" from the country's mounting economic problems and a growing insurgency by communist guerrillas.

While most observers thus see the medals story as a pretext for a crackdown, no one disputes that Marcos is highly sensitive about his war record. During the fight against the Japanese in World War II, Marcos reportedly was wounded several times and emerged as the most decorated Filipino veteran of the war, according to his supporters. That status has greatedly helped his political career.

However, a retired Philippine Army major and opposition figure living in the United States, Bonifacio Gillago, suggested in a monograph based on U.S. records that some of Marcos' reported exploits were exaggerated and that he was not present at certain battles for which he was decorated.

Local press accounts have given various numbers for Marcos' war medals ranging from 26 to 33. Among them are the American Distinguished Service Cross, two U.S. Silver Stars and four Purple Hearts.

Marcos' official World War II biography also claims that he was recommended for the highest American award for valor, the Congressional Medal of Honor, for almost single-handedly delaying the fall of Bataan, but that the papers got lost in transit to Corregidor.