Police operations in Iraq's eastern region of Diyala have led to three hostages being freed and the dismantling of several extortion gangs, the local police chief said on Sunday.

Kidnapping for ransom in Baghdad and elsewhere in the country is a phenomenon that has grown to such an extent that the government has publicly declared tackling it would be one of its priorities.

"Kidnappings are a crime -- we deal with them as we deal with terrorism," Diyala province police chief Lieutenant General Jamil al-Shammari told reporters.

"We managed over the past 24 hours to free three people who had been kidnapped thanks to good tip-offs that led us to their captors," he said.

Shammari said a series of operations had reduced the number of kidnappings in Diyala, an ethnically mixed province where the security forces, backed by Iran and Shiite militias, recently notched up significant victories against the Islamic State group.

While some abductions are a direct result of the sectarian tension that has grown since jihadists took over part of Iraq this year, others are the work of extortion gangs that have prospered in the confusion.

Prime Minister Haider al-Abadi recently announced the creation of special crisis cell to tackle kidnappings, which Baghdad's top security official said were a greater threat to the capital's security than the jihadists.

Thousands of people fearful of kidnappings have been forced to leave their homes or because they lost everything they had in paying a ransom.

The militias that have helped government troops defend the country against IS fighters have been blamed for abductions and other abuses in areas they control.

However, many kidnappings are also carried out by criminals posing as members of the security forces or militias.