CAIRO (AP) — Swarms of jellyfish have descended on Egypt's northern coast, keeping vacationers out of the water and stirring debate over a recent expansion of the Suez Canal.

The nomad jellyfish is native to the Indian Ocean and the Red Sea but has been turning up in the Mediterranean in growing numbers in recent years.

Experts say they are coming through the Suez Canal, which was first built in 1869. It has been expanded on a number of occasions, most recently in 2015, through a multi-billion-dollar project that the government touted as an historic achievement.

Egyptian officials have set up a committee to investigate the jellyfish invasion, but deny the recent canal expansion is to blame.

Marine experts said this week that other environmental factors may have contributed to the phenomenon.