BAGHDAD, Jan. 12 (Xinhua) -- A local woman "apparently" killed two Islamic State (IS) militants by poison in revenge for the killing of her son and her husband by the extremist militants in Iraq's eastern province of Diyala, a local police officer said.

The two IS militants broke into the house of the 47-year-old widow, who is originally a relative to them, in a village located some 65 km northeast of Baghdad, and forced her to prepare a meal, the police officer told Xinhua on condition of anonymity.

The woman prepared the meal, poisoned it and fled her house and the village after the militants left, the source said.

Later on, many IS militants broke into her house and when they did not find her, they set fire to the house and searched some nearby houses in the village, the source added.

The militants told the villagers that the two poisoned militants were dead, according to the source.

The widow's act came after the killing of her 16-year-old son in 2015 by IS militants and the killing of her husband earlier in 2011 by the extremist militants after he joined U.S.-backed Sahwa groups, also known as Awakening Councils who fought al-Qaida militants in Iraq.

Sadiq al-Husseini, head of the security committee in Diyala provincial council, told Xinhua that residents across the province are increasingly rejecting the extremist militants and this can be felt by the increasing cooperation by the residents with the security forces.

"Some of Diyala's areas witnessed a sort of popular uprisings against the extremist militants and some residents fought alongside the security forces. This is an important indicator that will contribute to the eradication of extremism," al-Husseini said.

Samir Musa, a security expert, told Xinhua that "there are many incidents carried out by the people against the militants of the terrorist organization in retaliation to their earlier crimes, but those people are keen to keep such acts unrevealed for fear of reprisal killing from the families and relatives of the extremist militants."

Musa said that there is an "undeclared war" currently being waged in the areas once under control of IS militants. "Many people refuse to cooperate with the extremist militants, and some of them took up arms against the terrorist organization."

The security situation in Iraq has been dramatically improved after Iraqi security forces fully defeated the extremist IS militants across the country late in 2017.

However, small groups and individuals of extremist militants melted or regrouped in urban and rugged areas, and have been carrying out attacks against the security forces and civilians despite operations from time to time to hunt them down.