TEHRAN, Iran (AP) — Iran’s Foreign Ministry says it’s holding the U.S. responsible for the fate of Iranians kidnapped in Syria.

The state IRNA news agency says the ministry summoned the Swiss envoy in Tehran late Monday to stress that Iran expects Washington to use its influence to secure the Iranians’ release. The Swiss look after U.S. interests in Iran since Tehran and Washington have no diplomatic relations.

Syrian rebels snatched 48 Iranians off a bus just outside Damascus Saturday. Iran says those abducted were pilgrims visiting a shrine but their captors claimed in a video broadcast Sunday they were on a “reconnaissance mission.”

Syria’s close ally Iran has criticized the U.S., Turkey and some Gulf states for supporting the Syrian rebels. It has also asked Turkey and Qatar to help return Iranian captives.