Excavations begin Monday of an unmarked mass burial site at a former mother and baby home in western Ireland suspected of containing the remains of hundreds of infants and young children.

The planned two-year probe by Irish and foreign experts in Tuam comes more than a decade after an amateur historian first uncovered evidence of a mass grave there.

Subsequent 2016-2017 test excavations found significant quantities of baby remains in a subterranean disused septic tank at the location, which now sits within a housing complex.

Scientists say the remains are largely mixed together, the BBC reports, and a number of methods will be used to try to put remains back together and, where possible, identify them.