DIYARBAKIR, TURKEY -- Kurdish rebels, in their sixth year of an increasingly bloody guerrilla war against the Turkish government, appear to be gaining grass-roots support, according to politicians, diplomats and other analysts.

The last two months, during which 140 people on both sides have been killed, were the most violent since August 1984, when the Marxist Kurdish Workers Party (PKK) started fighting in southeastern Turkey for independence for the country's 10 million Kurds.

Using better intelligence-gathering and helicopters, the security forces have made some headway in the war, which has claimed nearly 2,000 lives.

But the government's tactics have sparked some political backlash.

This spring, for the first time, anti-government demonstrations for a separate Kurdish cultural identity erupted in more than a dozen towns and cities in the Kurdish section of Turkey, a mountainous region the size of New England.

The demonstrations by thousands of Kurds -- some spontaneous, others prompted by the guerrillas -- followed warnings by Kurdish moderates that the security forces' widespread use of torture, wholesale arrests, routine beatings and other human rights abuses were alienating many Kurds. The government's harsh policy has drawn criticism from Amnesty International and others.

Many ordinary Kurds, who initially were horrified by atrocities carried out by the Kurdish rebels, now express sympathy with the guerrillas.

"The security forces mistakenly think they can stamp out all forms of Kurdish political life," remarked a Turkish academic who recently visited the southeast and requested anonymity. "Government policy is a classic case of too little, too late. Kurds don't want independence. They want freedom to be Kurds."

While Turkey was caught off guard by the demonstrations, it struck back on April 9, issuing sweeping powers to the region's governor. Critics said the governor, Hayri Kozakciolgou, already ruled under the civilian equivalent of martial law.

In a recent interview in this southeastern city, regarded by many as an unofficial capital of Turkish Kurdistan, the governor said he had no intention of "acting like a sultan." Kozakciolgou is empowered to seize newspapers and printing plants, impose fines of up to $50,000 and deport anyone from the region at will.

Fear of falling afoul of the decree has discouraged probing coverage of the southeast by the press, which now limits itself to publishing official communiques issued by the governor's office.

Since Kemal Ataturk founded the Turkish republic in 1923 the government has regarded any suggestion of a separate Kurdish identity as a threat to break up this heterogeneous state.

The Kurdish community in Turkey -- which accounts for half the Kurds who live in a wide arc stretching from the Soviet Union, Iran and Iraq to Syria -- is denied the right to use its language for official purposes and, for all intents and purposes, has no legal cultural existence.

Behind the scenes, according to informed sources, the Turkish military, with 60,000 troops in the region, is maneuvering to wrest overall responsibility for law and order from the governor, who controls 30,000 police, about 18,000 village guards and specially trained police commandos.

Kozakciolgou indirectly criticized army tactics initiated last summer by insisting that only slow, patient efforts to separate the guerrillas from the civilian population can lead to lasting pacification.

Even before the April decree, Kurdish moderates were depressed by signs of growing intolerance among Turkish officials, who in recent years had been moving gradually towards accepting a dialogue about Kurdish cultural rights.

Prof. Ismail Besicki, who since 1971 has spent more than a decade in jail for writing that Kurds form a separate ethnic group, is again on trial for publishing another book on the taboo subject.

Turkey's parliament is moving to strip five Kurdish members of their immunity. The opposition center-left Social Democratic People's Party expelled seven legislators for attending a conference on Kurdish issues organized last October in Paris by French President Francois Mitterrand's wife, Danielle.

Much of the hardening of government thinking is ascribed to the PKK's comeback after the end of the war between Iran and Iraq in 1988, which deprived them of sanctuary in northern Iraq. Nearly two years later, the PKK has succeeded in reestablishing bases in Iraq, maintaining others in Syria and opening new ones inside Iran.

Intelligence analysts estimate PKK strength inside Turkey at 1,500 to 2,000 armed men. Perhaps 1,500 others are either poised along Turkey's borders or training in camps run by PKK leader Abdullah Ocalan in the Syrian-controlled Bekaa Valley in Lebanon.

Although the guerrillas still use hit-and-run tactics in Turkey from bases across the borders, Western analysts are convinced that the PKK has sunk deep enough roots in Turkish villages to survive without dependence on foreign sanctuaries.

Clashes have spread as far north and east as the region around Mt. Ararat, near the Soviet border, and west to Elasig. But 60 percent of the fighting remains centered on the triangle linking Mardin, Siirt and Hakkari, close to Turkey's frontiers with Iraq and Syria.

As long as hostilities remain bottled up in the southeast, diplomats and analysts doubt the war will destabilize the government. But Turkish officials worry that the rebellion will spread to Adana, Ankara, Izmir or Istanbul, cities with large Kurdish communities. Recently police in Ankara, Istanbul and Malatya broke up armed cells of Kurdish Islamic fundamentalists.

"If Kurdish terrorists hit schools, police stations or army barracks" outside the southeast, said Ugur Mumcu, Turkey's leading specialist on terrorism and a columnist for the daily Cumhuriyet, "the army will be tempted to step in."