Kurdish guerrillas claimed today they have killed or wounded 7,000 Iraqi soldiers in fierce fighting in northeastern Iraq. They said nearly 2,000 civilians also died. The guerrillas acknowledged several of their bases have been overrun. They said the bases fell after repeated poison gas attacks. There was no independent confirmation of the Kurdish claims. Turkish officials said that about 90,000 Kurds, including some wounded guerrillas, have fled across the frontier in recent days. ``Most of the Kurdish civilian casualties are from constant Iraqi poison gas attacks on their villages and settlements,'' a spokesman for the Kurdish Democratic Party told The Associated Press by telephone. ``Iraqi troops has overrun our bases in Zakho and Dahok provinces, but our guerrillas are still engaged in fierce fighting inside Iraq to save our civilian population from severe Iraqi reprisals,'' he said. The spokesman, based in a West European capital, has given information to the AP on several other occasions. He declined to give his name for security reasons. Iraq's 3.5 million Kurds have been waging their separatist struggle on and off for 50 years. Kurdish officials said many of the refugees were injured in mustard gas attacks, but there was no official Turkish confirmation. Kurdish guerrillas are battling an estimated 60,000 Iraqi troops who are supported by tanks, artillery, fighter-bombers and helicopter gunships. The Iraqis launched a major offense Aug. 26 against the rebels. The guerrillas claimed the Iraqis have carried out scores of poison gas attacks in recent weeks against Kurdish villages and guerrilla bases. Iraq has denied using chemical weapons, outlawed under a 1925 Geneva treaty. The spokesman stressed that Kurdish ``resistance is continuing'' in the Amadiyah and Sherwan regions. He said the guerrillas were trying to avoid set-piece battles with the heavily armed Iraqis and were ambushing military columns in coordinated hit-and-run attacks. He said guerrillas shot down four Iraqi helicopter gunships in the last few days and killed or wounded 7,000 government troops in recent fighting. Kurdish casualties were listed as 250 guerrillas and 1,900 civilians killed, with 5,000 civilians wounded. The spokesman said the Iraqis have not been able to seal off the border with Turkey. This is the only escape route for civilians. In a separate statement, Kurdish Democratic Party leader Massoud Barzani denied press reports that he had sought asylum in Turkey. ``Our decision is to remain with our beleaguered people ... and to continue our resistance for the survival of the Kurdish people.'' About 20 million Kurds lived in the mountainous region where the borders of Iran, Iraq, Turkey and Syria meet. Kurdish rebels joined forces in November 1986 and launched an increasingly effective campaign against Baghdad. Iraq's intensified operations against the Kurds came after an Aug. 20 cease-fire with Iran took effect.