The Punjab Assembly on Wednesday unanimously passed a resolution, seeking an apology from the British government for the Jallianwala Bagh massacre.
Parliamentary Affairs Minister Brahm Mohindra moved the resolution and political parties, cutting across party lines, supported it.
"The tragic massacre of innocent protesters in Jallianwala Bagh in Amritsar on April 13, 1919 remains one of the most horrific memories of British colonial rule in India. This shameful military action against locals peacefully protesting against the oppressive Rowlatt Act has since received worldwide condemnation," the resolution said.
"However, its proper acknowledgement could only be by way of a formal apology by the British government to the people of India as we observe the Centenary of this great tragedy," the resolution said.
"This August House thus unanimously recommends to the state government to take up this matter with the government of India to impress upon the British government to officially apologise for the massacre of innocent people at Jallianwala Bagh, Amritsar," the resolution said.
Opposition parties AAP, SAD-BJP and Lok Insaaf Party supported the resolution.
Troops of the British Indian Army, under the command of Colonel Reginald Dyer, had fired on civilians who had gathered at Jallianwala Bagh for a peaceful protest on April 13, 1919 and scores of people had died.