A 3,500-year-old stone ax engraved with an ancient northern Indian script found in the country's south could establish a closer historical link between the distinctive regions, an archaeologist said Monday.

The ax was found by a schoolteacher, V. Shanmuganathan, in a mangrove forest in a village in the southern Tamil Nadu state in February, said T. S. Sridhar, commissioner of the state's archaeology department.

The polished hand-held stone ax has four seals on it that are written in a script used around 1,500 B.C. in the Indus Valley in northern India, Sridhar told The Associated Press in a telephone interview from Madras, the capital of Tamil Nadu state.

Such seals are most commonly associated with the ancient cultures of Harappa and Mohenjo Daro, ruined cities that both lay in modern-day Pakistan, thousands of miles to the north of Tamil Nadu.

The presence of the script on the ax is a strong indication that the Neolithic Aryan people of northern India penetrated much father south than previously believed.

"It shows that there has been a link between south of India and the rest of the country," Sridhar said.

The find is "the greatest archaeological discovery (in) a century in Tamil Nadu state," said Iravatham Mahadevan, an expert on the Indus script who is not connected with the find.

He was quoted in The Hindu newspaper.