Tokyo (PTI): A piece of ironware excavated from a Turkish archaeological site is about 4,000 years old, making it the world's oldest steel, Japanese archaeologists said on Thursday.

Archaeologists from the Middle Eastern Culture Center in Japan excavated the 5-centimetre piece at the Kaman-Kalehoyuk archaeological site in Turkey, about 100 kilometers southeast of Ankara, in 2000. The ironware piece is believed to be a part of a knife from a stratum about 4,000 years old, or 2100-1950 B.C., according to them.

An analysis at the Iwate Prefectural Museum in Morioka showed that the ironware piece was about 200 years older than one that was excavated from the same site in 1994 and was believed to be the oldest steel so far made in 20th-18th centuries B.C.

The ironware is highly likely to have been produced near the Kaman-Kalehoyuk site as a 2-cm-diameter slag and two iron-containing stones have also been excavated, Kyodo news agency quoted the archaeologists as saying.

Hideo Akanuma, an archaeologist at the Iwate Prefectural Museum, said the fresh finding led to a change in the history of iron and steel production, noting that such production was earlier thought to have begun in the Hittite kingdom dating in the 14th to 12th centuries B.C.