The army can be called in whenever there's any protest or crowd.

The law only allows this when the assembly is unlawful, cannot be dispersed by ordinary means, and public security genuinely requires it — it's meant as a last resort, not a routine tool.

Once summoned, soldiers can use any force they want to clear the crowd.

The law explicitly requires the officer to use the least force and cause the least injury to people and property consistent with dispersing the assembly and making arrests.

Bharatiya Nagarik Suraksha Sanhita, 2023

Section 149

Use of armed forces to disperse assembly

(1) If any assembly referred to in sub-section (1) of section 148 cannot otherwise be dispersed, and it is necessary for the public security that it should be dispersed, the District Magistrate or any other Executive Magistrate authorised by him, who is present, may cause it to be dispersed by the armed forces.§

(2) Such Magistrate may require any officer in command of any group of persons belonging to the armed forces to disperse the assembly with the help of the armed forces under his command, and to arrest and confine such persons forming part of it as the Executive Magistrate may direct, or as it may be necessary to arrest and confine in order to disperse the assembly or to have them punished according to law.§

(3) Every such officer of the armed forces shall obey such requisition in such manner as he thinks fit, but in so doing he shall use as little force, and do as little injury to person and property, as may be consistent with dispersing the assembly and arresting and detaining such persons.§

Why this exists

This provision continues, almost word for word, Section 131 of the old Code of Criminal Procedure, 1973, which itself descended from colonial-era public order law. It exists for extreme situations — riots, large-scale violence, or insurrection-like unlawful assemblies — where ordinary police cannot control the crowd and civil authority genuinely needs military muscle to restore order. The safeguards (magistrate's presence, necessity requirement, minimum-force rule) were designed precisely because unchecked military force against civilians has historically caused tragedies, and the law tries to keep such power under civilian magisterial control and proportionality limits.

How courts read it

There is no major reported Supreme Court judgment interpreting this specific provision (or its CrPC predecessor Section 131) in detail, since its use is rare and mostly discussed in the context of historical events like the 1919 Jallianwala Bagh firing (which predated this statutory framework but shaped public and judicial sensitivity to military force against civilians). Courts and commentators generally emphasise, consistent with the text itself, that the power is a last resort, requires a magistrate's actual presence and judgment of necessity, and that any excess force by the armed forces beyond what is 'consistent with dispersing the assembly' can attract legal liability.

Common misconceptions

Myth: The army can be called in whenever there's any protest or crowd.
Fact: The law only allows this when the assembly is unlawful, cannot be dispersed by ordinary means, and public security genuinely requires it — it's meant as a last resort, not a routine tool.
Myth: Once summoned, soldiers can use any force they want to clear the crowd.
Fact: The law explicitly requires the officer to use the least force and cause the least injury to people and property consistent with dispersing the assembly and making arrests.