Updated

Ireland's government launched an investigation Tuesday into the high mortality rates and mistreatment among babies who died decades ago in homes for unmarried mothers, plunging the country into another painful examination of the past.

The investigation followed revelations last week that hundreds of children died at a former Roman Catholic church-run "mother and baby" home in western Ireland. Amid the outcry, Prime Minister Enda Kenny promised an extensive inquiry and acknowledged that for decades, children born out of wedlock were treated as "an inferior subspecies."

"This was Ireland of the (19)20s to the '60s — an Ireland that might be portrayed as a glorious and brilliant past, but in its shadows contained all of these personal cases, where people felt ashamed, felt different, were suppressed, dominated," he said. "And obviously the question of the treatment in the mother and babies homes is a central part of that."

The inquiry will seek to determine what occurred, rather than try to apportion blame. It will look at the high mortality rates at the homes, the burial practices at these residences, illegal adoptions and whether vaccine trials were conducted on the children.

A researcher has found records showing that 796 children, mostly infants, died in a home in Tuam, County Galway, which operated from 1925 until 1962. Residents suspect they were interred in a nearby field, including in a disused septic tank.

Ireland had some 10 such "mother and baby homes" run by different orders until the 1960s. A Protestant-run home will also be included in the inquiry.

The inquiry follows four other fact-finding investigations in Ireland, including examinations of the cover-up of child abuse inside industrial schools and by priests in Dublin, Cork and the southeast county of Wexford.

Tanya Ward, chief executive of the Children's Rights Alliance, said a commission must be granted full power to compel witnesses to produce evidence and supply documents.

"Uncovering the dark history of how we treated unmarried mothers and their children is vital for us to truly acknowledge and understand our past," she said in a statement. "This is the missing piece of the jigsaw."