Scores of police agents watch the streets, market and cafes of this city and its large ethnic Turkish population. Guards at roadblocks turn back foreigners seeking to visit. Residents say they are threatened with two years in prison for communicating with the outside world.

For at least 17 months, Kurdzhali has been a focal point of what Bulgaria's Communist government portrays as a voluntary "revival" of Bulgarian roots among its Moslem population. Yet, when they can speak, in stolen moments on street corners, park benches, and cafes, ethnic Turks here describe a campaign of terror meant to force them to abandon their names, language and culture.

"They shot many. I don't know how many, but it was many," one middle-aged man told western reporters allowed to visit here last Saturday. "There is no life here. You are followed, I am followed."

In separate interviews, two residents said that police killed numerous ethnic Turks as the assimilation campaign reached its height here in early 1985. Others said they remain prohibited from speaking Turkish in schools, jobs and public places, that they had been barred from attending mosques and that those who refused to switch their Islamic names to Bulgarian had been arrested.

"It was terrible," said Mehmet, a young man who added, with a grimace, that his official name was now Miliev. "Yusef became Ivan," said another young man, an ethnic Bulgarian.

The fearful accounts appeared to support reports by western diplomats and human rights organizations that Bulgaria has become the site of one of the harshest ongoing suppressions of an ethnic minority in a region plagued for centuries with national clashes. Since late 1984, authorities have reportedly sought to force all of the estimated 900,000 ethnic Turks in a population of 9 million to accept new identities as "Bulgarian Moslems."

Amnesty International reported last week that more than 100 ethnic Turks had been killed in clashes with police who conducted sweeps in Turkish areas during the name-changing campaign last year. Hundreds of persons were arrested and the homes of some families who refused to cooperate were bulldozed, the organization said.

The repression has drawn repeated protests from Turkish President Kenan Evren, damaged Bulgaria's relations with Islamic countries and appeared to contribute to a strain in relations between the Bulgarian Communists and Soviet leader Mikhail Gorbachev.

Yet conditions in Kurdzhali and statements by Bulgarian officials last week indicated that authorities have no intention of relaxing the pressure on ethnic Turks -- or even admitting that they exist.

"There are no Turkish areas in Bulgaria," said Bojan Traikov, a government spokesman, during a press conference in Sofia last week. The ethnic Turks, he said, were "Bulgarians by birth" who had voluntarily joined "a process of revival" of their Slavic roots, changing their names in the process.

"This is not an official attitude," he said of his account. "It is a historic truth." Traikov described western journalists who have reported on instances of repression as "devils" who have deliberately distorted the situation.

The roots of the problem date to Bulgaria's occupation by the Turkish Ottoman Empire for nearly 500 years beginning in the 14th century, an epoch usually referred to even in casual Bulgarian accounts as "the Turkish yoke." Some Bulgarians adopted Islamic culture, and many ethnic Turks moved to the rugged, mountainous southern and northeastern areas of the country.

Kurdzhali, a town of about 40,000, was founded by a Turkish military commander named Kurdzi Ali early in Turkish rule and did not become part of Bulgaria until 1913, 35 years later than the bulk of the country. Some 35 miles north of Bulgaria's border with Greece, it is an agricultural center where a traditional outdoor market and stately mosque mix with modern offices and a cafe-lined promenade.

The city is believed to retain a majority ethnic Turkish population, and many villages in the surrounding valleys and low mountains are almost entirely Turkish. In recent years, the birthrate among ethnic Turks has been high, while that of Bulgarians around the country has been near zero.

Diplomats believe that concern about the population trends and potential demands by ethnic Turks for regional autonomy helped provoke the drastic increase in official pressures for assimilation. Government authorities, who had abolished Turkish schools in 1974, this year completed a census that did not register the existence of any non-Bulgarian populations. The last census a decade ago reported 500,000 ethnic Turks in the country.

The attempt to erase Turkish culture has been so complete that the one newspaper printing in Turkish switched to Bulgarian, and restaurants have removed listings on their menus for "Turkish" coffee. Newspapers have reported findings by Bulgarian anthropologists who have excavated burial grounds and concluded that skulls found there belonged to proto-Bulgarians, not Turks.

Since December 1984, Kurdzhali and other major Turkish settlements have been sealed by roadblocks, and western diplomats and reporters seeking to travel in the area have been turned back. Three western reporters seeking to visit Kurdzhali independently on Thursday were stopped.

Following repeated inquries from reporters at press briefings held during Bulgaria's Communist Party conference, the government press agency transported a group of journalists to the town on Saturday. The journalists were followed closely by police agents deployed through the city but were allowed to circulate for several hours.

Residents who were approached in cafes, on street corners around the busy central market, and in the town park appeared accustomed to the heavy security presence. "We can't talk, there are police all over the place," said a man in the market. In a bar, several ethnic Turks who had begun a conversation with reporters suddenly fell silent when a passer-by conspicuously looked in.

In the city's bus station, a young man was asked if he spoke a foreign language. "Turkish," he replied in English. Then, throwing a quick, fearful glance over his shoulder, he added in Russian, "I can't."