Thousands of supporters descended from all over the state to Nellore district, where former chief minister N Chandrababu Naidu was scheduled to address a public meeting on Wednesday.
The rush began as people pressed forward to get a glimpse of the now leader of the opposition as his convoy reached the venue in the evening. Due to the melee of a large number of people in one place, a cement railing broke and at least 20 people fell into an open drainage canal.
Although the drain was not deep, people fell over one another, which led to suffocation and injuries. Members of Mr Naidu's Telugu Desam Party (TDP) immediately jumped into rescuing those who fell, but two people died on the spot, the local police said.
The injured were rushed to a nearby hospital, where six people succumbed. The eight victims, including two women, have been identified as supporters of Mr Naidu's political party.
Mr Naidu stopped his roadshow mid-way and went to the hospital to meet the victims and their families. He later announced Rs1,000,000 (£10,023) ex-gratia each for the kin of the dead and vowed to support the education of the children of the victims.
"This is a sad incident. I'm feeling very sorry about it," Mr Naidu, one of the tallest political figures in the state, told reporters on Thursday.
Mr Naidu's party shared pictures of him comforting the family members of the victims. "He gave courage to the family members and assured them that the party will support them in all ways," TDS said in a tweet.
An investigation has been launched into the stampede to ascertain the cause of the deaths, Nellore superintendent of police Vijaya Rao said.
“We are investigating the case from all angles. Soon we will find the exact cause,” he added.
Meanwhile, prime minister Narendra Modi condoled the deaths and announced Rs200,000 (£2,000) for the bereaved families and Rs50,000 (£500) each to the injured.
"Pained by the mishap at a public meeting in Nellore, Andhra Pradesh... May the injured recover soon," he said.