As Iraqi forces, aided by Shiite militiamen, took control Wednesday of the northern city of Tikrit, they found vehicles laden with explosives and buildings that might be booby-trapped.

CNN senior international correspondent Arwa Damon, who was in Tikrit on Tuesday, saw a large mechanical digger packed with explosives that Iraqi forces had to disarm. The troops, she said, were cautious when they entered buildings in case they were wired to explode. Plumes of smoke rose from burning buildings in the background.

Near former Iraqi dictator Saddam Hussein's presidential palaces compound -- Tikrit is Hussein's birthplace -- the CNN team also saw a destroyed truck with a large machine gun mounted on the back. Iraqi forces said they had fired an RPG at the truck, killing three ISIS fighters. ISIS was ejected from the palaces compound in fierce fighting, they said, adding that there may still be booby traps.

Federal police said they dismantled hundreds of IEDs (improvised explosive devices) Wednesday. CNN heard at least 16 explosions, some very loud, which police said were controlled.

The potential booby traps were political as well as physical. Officials are concerned about the behavior of the conquerors, particularly the Iranian-backed Shiite militiamen who helped Iraqi troops. Officials fear the militiamen might take "scorched earth" reprisals for the reported massacre of Shiite air force cadets by ISIS fighters in Tikrit last year.

Much of the population of Tikrit is, like ISIS, Sunni Muslim. And officials fear that reprisals by Shiite militias against the Sunni population could stoke local anger, jeopardizing the government's ability to hold onto Tikrit and pull the country together. Sectarian resentment helped fuel the rise of ISIS in the first place.

(CNN)