ENKOPING, Sweden — The discovery of Arabic characters that spell “Allah” and “Ali” on Viking funeral costumes in boat graves in Sweden has raised questions about the influence of Islam in Scandinavia.

The grave where the costumes were found belonged to a woman dressed in silk burial clothes and was excavated from a field in Gamla Uppsala, north of Stockholm, in the 1970s, but its contents were not cataloged until a few years ago, Annika Larsson, a textile archaeologist at Uppsala University, said on Friday.

Among the contents unearthed: a necklace with a figurine; two coins from Baghdad; and the bones of a rooster and a large dog.

Dr. Larsson discovered the Arabic characters in February, as she was preparing some of the items for an exhibition on Viking couture in Enkoping, Sweden. She had been trying to recreate textile patterns for the exhibits — by comparing motifs on the burial dress with a silk band found around the head of a skeleton in a Viking grave at Birka, Sweden — when she discovered Kufic characters of Arabic.