The passports were found by Ethiopian troops and handed to US soldiers in the area, according to Expressen.
“According to what the Ethiopian troops told the Americans, the passports were found in the area attacked by the Americans on January 7th,” said Nina Ersman, spokeswoman for the Swedish foreign ministry.
A spokesman for the Somalian government said earlier this week that Swedish citizens were among those killed and taken hostage in the area.
“But the spokesman also said that the information was not confirmed and that the government was trying to verify it,” said Ersman.
Sweden does not have a diplomatic presence in the area, and the foreign ministry has therefore found it hard to obtain confirmation of reports of dead or imprisoned Swedes.
The foreign ministry has also been unable to give estimates of the number of Swedish citizens who have participated in the fighting.
“We have for a long time been strongly advising against travelling to this area and we have been encouraging those who are there to leave the country,” said Nina Ersman.