Civilians in Serbia are still in danger from thousands of unexploded cluster bombs almost a decade after NATO bombing of Yugoslavia, local media reported Saturday.

A study by Norwegian People's Aid said that some 2,500 unexploded pieces of cluster ordnance were scattered across 15 municipalities, mainly in southern Serbia near the border with Kosovo, and the second largest city of Nis.

Around 160,000 civilians were at risk and it would take between 12 and 23 years to clear the areas if the current rate of clearance continued, the study said.

Serbia needs around 38 million dollars to dig out and defuse unexploded cluster bombs - canisters that open in flight and eject dozens of bomblets, some of which can lay unexploded for years.

NATO planes scattered some 37,000 cluster bombs over Yugoslavia, killing 31 people and injuring 160, during its 78 days of attacks to end Serbia's crackdown of Albanian insurgents in Kosovo.

Kosovo declared independence from Serbia in February 2008 and was recognized by more than 50 countries including the United States and most of the European Union.

Last year, 93 countries signed an international treaty on banning the cluster bombs. However, major producers and users such as the United States, Russia and China have not signed the treaty.