It doesn't take long for a newcomer to feel the temper of the times in this rainy mountain capital. A glance at the headlines in the official newspaper, the Ethiopia Herald, is sufficient.

"Counterrevolutionary Bandits Liquidated," says a typical item "Militia Assist in Wiping Out Antirevolutionaries." Search Teams Discover Arms." "Progressive Students Expose 19 Agents." "Workers of Seven Factories Armed."

These are accounts of the systematic campaign by the leftist military government to cut down its opposition. For a week, armed militamen and search teams have been going through the capital house by house, looking for weapons, antigovernment leaflets, cash or anything else that would reveal the occupants as "paid agents" of the opposition, as anarchists, counterrevolutionaries, or reactionaries.

Nobody knows how many people have been arrested or killed in this drive but the numbers are rising steadily. Sometimes the bodies of the liquidated are shown on television, including the mangled corpse of a reputed opposition leaders who hurled himself out an eighth-floor window rather than let himself be taken alive.

The government has published special telephone numbers on which "allies of the revolution" may denounce "antirevolutionaries, hired assassins, persons trying to run away or hide weapons used for killing revolutionaries and antirevolutionary purposes."

In practice, according to nervous Ethiopians, this means that anyone can be denounced as an enemy of the revolution for any reason, or for no reason. Many of those named in this way have been arrested.

After some days of this, the government reported the campaign was making progress and the curfew, which had been 10 p.m., was moved back to midnight. But that means little because hardly anyone goes out after dark anyway. When darkness comes, the shooting begins.

Supporters of the government battle it out with their opponents, or with themselves, and those who are not involved find it advisable to stay home. Most shops, restaurants and theaters are closed by nightfall. By dinner time, the loudest sounds in this city of about 1.1 million are the gunfire and the endless baying of the hyenas.

This is a city where a luncheon companion stops talking as a busboy clears the dishes. Who knows which side the busboy is on?

The atmosphere has not deterred the young men who approach strangers on the street, offering to talk politics and perhaps deliver some antigovernment pamphlets. They claim to be students cut adrift by the closing of the university, but they really are sophisticated panhandlers.

A typical example is a young man named Tulu. He speaks excellent English, has an extensive political vocabulary, and freely criticizes the government junta led by Lt. Col. Mengistu Haile Mariam. Tulu says that Mengistu, who he calls "the man in the position," is "a fascist despite his and what the people want is a rival claims to be a Marxist revolutionary, Markist group, led by civilians, who introduce 'scientific socialism.'

Tulu's favoriate spot for this kind of chat is a bench behind the 16th tee of the Addis Ababa golf club. His political commentary cannot be overheard there. Nor can the appeal for funds that inevitably folows it. The some game went on before the Ehiopion revolution of 1974, but in those days the target of the criticism was the late Emperor Haile Selassie.

When the violent crackdown began last week, the government banned the sale of alcoholic drinks during the day. According to newspaper commentary, "It is not very flattering to Ethiopia that its people should be a nation of drunkards. However, it is a fact of life that alcoholism is becoming the genetic disease of the our not so-distant feudal past." The commentator said that "Alcohol is the cancer of Ethiopian society," and hailed the curb on its sales as a move in the right direction. But it has already been partially relaxed.

Addis Ababa is a city of rumor, suspicion and intrigue.

Last Sunday, the morning calm was suddently shattered by bursts of gunfire of the kind usually heard only at night. Traffic was cleared from Josip Broz Tito Avenue, a broad thoroughfare that leads up a hill to the junta's headquaters. Jeeploads of troops went roaring by.

A group of Iranian tourists trying to leave the Hilton Hotel for the airport was turned back. Pedestrians were stopped and searched.

Half an hour later, it was all over. The troops vanished as quickly as they appeared. The street was reopened. Nobody claims to know what it was all about, but there are many theories.

This lack of information helps explain the interest of foreign diplomats in an item that appeared recently in a Communist newspaper in Italy.

It was a translation of an interview that Mengistu gave to the official Cuban daily, Granma, during the visit of President Fidel Castro. In the interview, Mengistu either did or did not endore a proposal for federation of Ethiopia with its archrival neighbor, Somalia. According to the English translation of the Italian translation of the Spanish version in English or Amharic, it still is not clear.