Harare - The brother of abducted pro-democracy activist, Itai Dzamara, has vowed not to be deterred by state security's heavy handedness, as he continues to search for answers regarding the disappearance of his brother. According to NewsDay, Patson Dzamara said no amount of torture or intimidation would stop him from finding the truth about his brother, who was abducted over a year ago.Patson was brutally assaulted and arrested by security agents on Monday for protesting the abduction of Dzamara in front of President Robert Mugabe. He reportedly caught state security by "surprise" when he staged a one-man demonstration, waving a placard, demanding that Mugabe, 92, accounts for his missing brother.Mugabe was delivering a keynote address at the national sports stadium in Harare, marking the 36th anniversary of the southern African country’s independence from colonial rule.'This can never break my spirit'Patson said that he was ready for anything that state security might dish out to him as he searched for answers."This can never break my spirit. I knew what I was doing and I had budgeted for such a response from them. I didn’t care much about what would happen to me, as long as they got the message, and I will not be deterred by this," Patson was quoted saying.Dzamara, a father of two, was abducted by five men who stormed a barbershop in Glenview, Harare, while he was having a haircut in March 2015.He had been staging protests in Harare's Africa Unity Square, calling on Mugabe to step down.Human rights watchdog Amnesty International has since called for a thorough investigation into the brutal attack on Patson.Deprose Muchena, Amnesty International's Director for Southern Africa, described the attack as "appalling", adding that this was proof that Mugabe’s regime was prepared to lash out at anyone challenging its violation of human rights. "The irony that this happened on Independence Day will not be lost on people in Zimbabwe and is a blatant attempt to tighten the noose around freedom of expression. State security agents cannot be allowed to commit human rights violations with impunity," Muchena said in a press statement.