A group of parents whose children were killed in the Germanwings plane crash in March have written a scathing letter to Lufthansa's CEO, accusing him of ignoring their needs and feelings.

The parents of 16 students from the town of Haltern killed in the crash have accused Carsten Spohr of never having spoken with relatives to apologize.

In the letter, provided Tuesday by their lawyer, they say "we've heard nothing from you."

Lufthansa says Spohr has talked with many victims' families and attended several memorials.

The letter comes amid negotiations with Lufthansa, Germanwings' parent airline, over compensation.

Lufthansa has offered around 100,000 euros ($108,000) per family, depending upon its size.

The families say in their letter the offer "deeply insults us, and above all else our children."