A member of Iraqi federal police walks among rubble in the destroyed Old City of Mosul, Iraq August 7, 2017. REUTERS/Suhaib Salem

WASHINGTON (Reuters) - The World Bank on Tuesday approved $400 million in additional funding to help rebuild services to Iraqi areas recaptured from Islamic State militants after a three-year military campaign, the global development bank said.

The World Bank also said it would fund studies on how to involve the private sector in the reconstruction of Mosul’s airport and restoring public transport terminals as well as parts of the railway network.

“The package represents an additional financing to the Iraq Emergency Operation for Development Project ($350 million) approved back in July 2015 and already underway in seven cities in Diyala and Salah Ad-Din governorates,” the World Bank said in a statement.

It said the new funding would focus on rebuilding in five sectors - water and sanitation, electricity, health, transport and municipal services. The funds will also help with the restoration and preservation of cultural heritage sites in Mosul’s Old City, which was heavily damaged by fighting.

Iraqi government forces, backed by a U.S.-led coalition, retook Mosul in May - by far the largest city to fall under militants’ control - after nearly nine months of urban warfare.

Iraqi government officials have estimated it will take at least five years and billions of dollars to rebuild Mosul.