The six neatly uniformed, unarmed Libyan soldiers stopped, turned on their heels and started at the taxi as it drove by slowly along an otherwise empty street just inside the northern boundary of this war-ravaged capital.

Even in the confusion left in Ndjamena's shabby streets by months of often random combat, the Libyans were clearly distinguishable from ragged Chadian forces by their new green togs and shined black boots.

They were part of a two-battalion Libyan Army contingent that helped defeat rebel forces that had been battling Chad's transitional government for control of Ndjamena for nine months. In an effort to keep a low profile, the estimated 1,000 Libyans who participated in the fighting are bivouacked just north of the city, according to a well-informed source.

Western intelligence analysts say that as many as 4,000 Libyan troops have entered Chad in various regions, along with Soviet-made T54 tanks. Now, much to the consternation of Chad's neighbors, it looks as if the Libyans have come to stay and that their brand of Islamic revolution could be on its way to Ndjamena.

These fears, already sharp since Libyan soldiers turned the tide in the battle for Ndjamena last month, were heightened by an announcement Tuesday that Libya and Chad plan to merge.

Most of Chad's neighbors have large Moslem populations along Chad's borders and are nervous about the possibility that Libyans in Chad could export revolution to their civilians as part of a dream by the Libyan leader, Col. Muammar Qaddafi, to bring the area's Moslems into a Libyan-influenced pan-Islamic association.

It is the prospect of such Quaddafi-style destabilization in surrounding countries that has focused attention on the latest turn in Chad's 16-year civil war. As a central African launching pad for Quaddafi's pan-Islamic goals, Chad could mean much more to the region than it has in the 20 years since it acquired independence from France and slipped into chronic civil war.

In the meantime, however, the Libyans are staying out of sight, and the concerns of most Chadians in Ndjamena revolve around staying alive and keeping their property in the chaos produced by months of war among armed but little organized factions.

Since the end of fighting in mid-December with the Libyan-backed victory of President Goukouni Quedei, Ndjamena during the day has become a relatively relaxed city, at least compared to a year ago. At night, however, it is still dominated by fear and disorder as bands of armed soldiers or persons posing as them maraud neighborhoods and houses and demand money.

"Life is very difficult during the fighting," said Abdoulahi Harun, 40, who stayed in the city with his wife and four children from the time the latest round of fighting began last March. "But since the fighting stopped, people are more afraid because there is no security. The soldiers are robbing and raping."

The day after the fighting ended, on Dec. 16, Harun sent his family across the Chari River with thousands of other refugees fleeing Ndjamena to a six-month-old refugee camp in the northern Cameroon city of Kousseri.

As many as 10,000 people have fled Ndjamena to the camp since the fighting ended, according to refugee relief officials, swelling the numbers of the camp to 100,000, including those who had fled earlier in the year.

The block-by-block destruction of the downtown area of Ndjamena attests to intense battles among guerrilla factions for control of the city's business center and ultimately the entire city. Until the Libyans turned the tide with about five T54 tanks and attacks by Mig fighters, the rebels controlled the southern and eastern parts of the city into the center. The coalition of Goukouni's transitional government forces stretched from the north and west into the center.

One of the city's dominant structures, the domed roof of the Roman Catholic cathedral, was blown up by rockets during fighting over the city's main square, and only the shell of the building remains. Through the cross -- once filled with colored glass -- blue sky is visible. Closed steel grates on the front door are blackened by fire and twisted by heat.

The tan Grand Mosque has been shot up extensively throughout its inner courtyard, but its twin minarets stand virtually untouched.

The post office and a once popular outdoor restaurant across the street from it, La Poste, are bullet-pocked, vandalized frames. The two dozen shops that formed the city's shopping center for Westerners are gutted and looted, including the U.S. International Communication Agency's American Cultural Center. A half-dozen government and private office buildings have also suffered extensive rocket and mortar damage.

As you move away from the city center, however, evidence of the fighting becomes less and less until it disappears altogether in the labyrinth of sandy streets and traditional mud-walled houses in the Chadian neighborhoods. Goukouni's mansion and the modern houses of the former French quarter that surrounds it have not been touched. The last of 400 French civilians were evacuated with the last of 1,200 French troops in May.

Unlike the tense atmosphere that pervaded the city a year ago, armed guerrillas guarding the entrances of still-standing and functioning government office buildings seemed unconcerned about the comings and goings of a reporter. oSome of the most suspicious a year ago even smiled in recognition and waved him through into compounds and into offices without questions during a seven-hour revisit recently.

Until the fighting ended three weeks ago, Ndjamena was the seat of an 11-faction transitional government tryng to maintain a semblance of stability until elections could be held. The transitional government grew out of four conferences held in Nigeria in 1979 and was finally pieced together in November last year.

The most recent fighting was among 10 Moslem factions, each jockeying for power against the others. Goukouni's coalition was on one side and the insurgents of guerilla leader Hissene Habre, former minister of defense in the transitional government, were another, trying to push Goukouni's forces out of the capital with the help of a couple of factions.

The southern blacks, who long dominated the government under French influence, formed the 11th faction. Except for a few disastrous attempts to aid Goukouni in early stages of the fighting, they sat on the sidelines during most of the war for Ndjamena.

The blacks, about half of the country's 4 million inhabitants, include Christians and animists, believers in traditional African religions. Some observers believe that they will not readily accept a merger with Libya and being made a part of Quaddafi's militant brand of Islamic revolution. But for the immediate future, little is clear about what will happen in Chad.