HONOLULU (AP) — Honolulu is prohibited from buying land or proceeding with construction on the city center section of a planned rail line until more studies on the project are finished, a federal judge ruled Thursday.

The city may continue work on the western end of the rail line in the meantime, according to the decision issued by 9th U.S. Circuit Court of Appeals Judge Wallace Tashima. Honolulu may also conduct engineering and design work on the city center portion.