Hunger strike is a type of non-violent act, in which the participants would fast as an act of protesting the politicians, and to express their feeling, in order to achieve a particular target, such as changes in the government policies, rules and regulations. The people who are participating in hunger strikes would usually take only liquid food.
Sometimes, hunger strikes would be controlled by the police personal by making them to feed in a forcible manner, and they are actually doing like this, in order to save the precious lives of the protesters.
The practice of hunger strike can be traced from our ancient Puranas, and from the great epic Ramayana. When Rama has left his kingdom and went to the forest, after a short time, Bharata also went to the forest, and asked Lord Rama to rule the kingdom of Ayodhya. When Rama hesitated, Bharata had become angry, and decided to start the hunger strike. Then after the repeated requests made by Lord Rama, the affectionate brother Bharata stopped his hunger strike, and returned to Ayodhya.
Similarly ancient queens and Rishi Patnis would eat food only after their consorts taste the food first. Famous chaste women like Savithri and Nalayani had observed strict fasting for the welfare of their beloved consorts.
Ancient sages, kings and queens used to observe hunger strike, when they could not see the almighty even after doing severe penance on them. Even now, some mischievous children, when they are punished by their parents, they would start doing hunger strike in order to express their anger over them. In case of those children who are kidnapped by some unidentified persons, they would also perform hunger strike in order to create sympathy on them.