India's longest sea bridge has opened along the coast of Mumbai. The project was completed with financial and technical assistance from Japan.

The 22-kilometer Mumbai Trans Harbor Link was inaugurated at a ceremony on Friday. The bridge connects the central part of the western city with an area across the bay.

Construction began in 2018. More than 70 percent of the costs came from Japan International Cooperation Agency loans of over 242 billion yen, or about 1.7 billion dollars.

The structure comprises bridge girders assembled with Japanese technology.

Speaking at the ceremony, Indian Prime Minister Narendra Modi said, "I am especially grateful to the Japanese government for the cooperation it has given in building this bridge."

Mumbai is India's largest commercial city. The rapidly urbanizing area is home to about 18 million people, and the bridge is expected to ease traffic problems and air pollution.

Japan's ambassador to India, Suzuki Hiroshi, also attended the ceremony. He said Japan has the technology, experience and human resources to help Indian society develop even further.