Researchers in Taiwan have discovered what they believe is the island's oldest civilization, dating back about 20,000 years and belonging to a pygmy-like people that came from China, Southeast Asia or beyond, the team leader said on Friday.

Taiwan's government-run Academia Sinica, which found more than 200 stone tools at the Ba Hsien Cave excavation site on the island's east coast, will return next year to seek clues on who was living there, leader Tsang Chen-hua said.

The civilization was probably a dark-skinned people similar to Negritos, a term that covers several ethnic groups of short stature in isolated parts of Southeast Asia, Tsang said. Their exact origin and migration route in Asia remain a mystery.

"Where they're from is a good question. We propose saying they're Negritos, but we haven't found a human skull yet," Tsang said. "We need to go back to see if they're from China or the Indochinese peninsula."

Taiwan's Negritos, who once numbered as many as 90,000 but are now extinct, may have reached Taiwan from Madagascar via the islands of Southeast Asia, some scholars say. Others believe they came via China, 160 km (100 miles) away across the Taiwan Strait.

Ethnic Chinese people are Taiwan's racial majority today.

An 11-person Academia Sinica team, funded by central and local government departments, spent 10 months digging up the tools, Tsang said. They will continue the search next year.