CIZRE, Turkey (AP) _ Turkish Kurdish separatists and security forces clashed violently for a second day Sunday in the worst fighting of the 8-year-old Kurdish insurgency. At least 45 people were killed over the weekend.

An 18-year-old Kurdish girl set herself on fire in the western city of Izmir to protest the killings of Kurds, police said, and elsewhere, demonstrators shouted separatist slogans and waved the outlawed Kurdish flag.

In predominantly Kurdish southeastern Turkey, soldiers with armored vehicles blocked the road into the town of Nusaybin. Nearby, soldiers in green camouflage ponchos lay in muddy ditches under a driving rain, training their automatic weapons on the town.

Other soldiers, many wearing the blue beret of the army's elite special operations unit, perched with rifles atop concrete-block houses outside the town.

The army set up roadblocks throughout the southeast and placed several towns under curfew. Telephone service to much of the region was cut off.

Reporters saw a column of 10 military vans filled with soldiers heading toward Nusaybin from Mardin, farther north.

Authorities and news reports said Sunday's fighting killed at least 15 people and wounded 67 others in southeastern Turkey. Marxist guerrillas of the outlawed Kurdish Labor Party, or PKK, had called for a general uprising to mark a Kurdish holiday on Saturday.

The unrest indicating their increasing following among Kurds, who make up about one-fifth of the population in Turkey.

In the worst clash Sunday, demonstrators shouting separatist slogans attacked security forces with rocket launchers in Nusaybin, state-owned television reported. Ten people were killed and 20 wounded in the fighting, the regional governor's office announced.

Another clash Sunday between Kurds and security forces in the town of Yuksekova claimed five lives and left 32 wounded, including an army major, the semi-official Anatolia news agency reported.

Authorities detained 70 Kurds, Anatolia said.

In Izmir, 18-year-old Rehzan Demirel set fire to herself and died on an isolated mountain road in a Kurdish district, said a local police officer.

She left a note reading, ''I burn myself for my Kurdish nation,'' the officer said, speaking on condition of anonymity.

The girl's family had moved from Nusaybin about 20 years ago, the officer said.

Police detained 37 people in the southeastern towns of Hakkari and Viransehir on Sunday after Kurdish protests, Anatolia said.

In Hakkari, near the Iraqi border, demonstrators hung an outlawed red, green and yellow Kurdish flag in the city center and broke windows in government buildings, the agency added.

Four police officers and 11 protesters were injured in a clash, Anatolia said.

On Saturday, fighting involving Kurdish separatists erupted throughout the southeast as residents celebrated Newruz, the spring holiday considered the Kurds' national day.

Ten people were killed in Cizre, 15 in the nearby town of Sirnak and five in other towns, officials said.

More than 200 people remained jailed Sunday in the city of Van from violence a day earlier that left one demonstrator dead and 31 people injured, including eight police, Anatolia reported. The demonstrators destroyed about 300 stores, the agency added.

Cizre was quiet Sunday after a night of fighting. Security forces, apparently using night vision equipment, repeatedly directed streams of tracer bullets at rebel positions during the night.

Turkey had reinforced its already heavy military presence in the region ahead of the Kurdish holiday.

The rebels have been fighting for an independent state since 1984.

The Turkish Kurdish separatists have become more active since Kurds in neighboring Iraq rose against Saddam Hussein at the end of the Gulf War.

That revolt was crushed, but a U.S.-led Western force helped resettle the Iraqi Kurds, who now control northern Iraq. The Turkish Kurds appear to have been motivated by the Iraqi Kurds' success.