Answer the following questions in one sentence.

Which officer gave orders of firing in the Jallianwala Baug ?

The Jallianwala Bagh massacre also called the Amritsar massacre took place on 13 April 1919. The people had assembled there to condemn the arrest of two national leaders. Colonel Reginal Dyer ordered to block the entrance of the garden. Huge troops of the British army entered and openly rifled the Indians. It was a brutal and horrifying scene where 100 died and wounded. It later led to a series of protests and strikes all over the country.