TEHRAN, Iran (AP) — The Iranian government says that nearly 1,800 ancient artifacts have arrived in Iran as part of the return of thousands of antiquities loaned decades ago to the University of Chicago.

The government website says the artifacts arrived in Tehran on Monday, accompanied by two academics from the university.

This is the fourth consignment of artifacts to have been returned since 2004. Other shipments were also made in 1948 and 1950.

Iran loaned the artifacts to the University of Chicago's Oriental Institute more than 80 years ago for research, translation and cataloging after university archaeologists uncovered them in the 1930s at the site of the ancient city of Persepolis. Another 17,000 artefacts from the initial loan remain in the U.S.

Iran and the U.S. have not had diplomatic relations since 1979.