Workers found a piece of a wing from a passenger jet on the runway at Indonesia's main airport and investigators are trying to determine which plane it fell from, officials said Wednesday.

The 10-foot piece of wing was found Tuesday at Jakarta's Sukarno-Hatta international airport, said Yurlis Hasibuan, a senior air transportation official.

"It has been identified as a side engine cover, but we do not yet know which plane it came from," he said.

The wing piece was found on a runway used by planes on domestic flights as well as some cargo planes flying internationally, he said.

Last month, a similar-sized piece of wing fell from a jetliner minutes after it took off from the same airport.

The Boeing 737, which was operated by a local airline, landed safely but the incident added to safety concerns about commercial aviation in Indonesia.

The country suffered a series of accidents earlier this year that killed more than 120 people, leading the European Union to ban all the country's airlines from landing there.

The U.S. Federal Aviation Administration downgraded the nation's rating to its lowest category.

Experts say the industry is plagued by poor maintenance, rule-bending and a shortage of trained professionals.