Is there undisputable proof for Carthaginian child sacrifice? I know Roman sources wrote about it, and burned bones have been found, but those could be cremations. I read the last confirmed human sacrifice of the Carthaginians was in the late 4th century BC on Sicily. While the Romans buried 4 people alive during the second Punic war.
There are no conclusive archaeological evidence, and the status of child sacrifice in Carthage is a matter of debate. In general, while there used to be a strong consensus amongst historians that the Roman insistence on the Carthaginians' infanticide was more than war propaganda, in later years several historians have raised doubts about the actual status of the practice.
The child necropolis found in the precinct of Tanit in 1921 at Salammbo, is the more compelling and more often quoted evidence of infanticide. Up to 20,000 urns containing the cremated remains of children and animals are estimated to have been deposited at the Tophet (Hebrew for "roasting place"), from 800 BC to 146 BC. Some of the urns found were decorated with symbols relating to Tanit, an uncommon practice for Carthaginian burial places.
However, the necropolis might very well have been a children cemetery. Jeffrey Schwartz, a University of Pittsburgh physical anthropologist, inspected the remains of 540 children and found that:
...about half the children were prenatal or would not have survived more than a few days beyond birth, and the rest died between one month and several years after birth. Only a very few children were between five and six years old, the age at which they begin to be buried in the main cemetery. The mortality rates represented in the cemetery are consistent with prenatal and infant mortality figures found in present-day societies.
Source: Child Burials - Carthage, Tunisia, Jarrett A. Lobell
Furthermore, no temple - of Tanit or Ba'al-Hamon - has been found in the necropolis, although only a portion of the area has been explored and intense urbanization of modern day Carthage doesn't offer many opportunities for further excavations.
M'hamed Hassine Fantar, Director of Research at the Tunisian Institute of National Cultural Heritage, also strongly denies the possibility his ancient forefathers practice infanticide, and accepts the view that the Tophet hosted remains of children that died of natural causes, and were later cremated.
In all likelihood, the matter won't be concluded anytime soon - if ever. The razing of Carthage to the ground probably destroyed any conclusive evidence, and the Roman accounts are anything but reliable.