Greece's prime minister said archaeologists excavating an ancient mound in the country's north have uncovered what appears to be an important tomb, The Associated Press reported.

Prime Minister Antonis Samaras visited the excavation Tuesday and said in his statement the discovery "is clearly extremely important" and dates between 325-300 B.C, around the end of Alexander the Great's reign.

Alexander died in 323 B.C. and was buried in Egypt. His empire stretched from modern Greece to India.

The workers have so far unveiled a flight of 13 steps that lead to a broad path and masonry walls that are bordered with two carved sphinxes, Samaras said.

Archaeologists have yet to see who was buried in the tomb, which is near ancient Amphipolis, though they theorize it might belong to a senior ancient official, according to AP.

Excavator Katerina Peristeri has argued the mound was originally topped by a large stone lion that was exhumed about three miles away from the site about a century ago. The lion has been associated with Laomedon of Mytilene, one of Alexander's military commanders who became governor of Syria after the king's death, AP reported.

"The evacuation will answer the crucial question of who was buried inside," Samaras said.

A police guard has been placed around the fenced-off mound, according to AP.

The tomb is expected to be opened in the next two weeks.