(CNN) -- Prominent human rights activist Al-Amin Kimathi was released from custody Monday at the outset of the trial for suspects in the fatal July 2010 bombings in Kampala, Uganda.
Ugandan High Court Justice Alphonse Owiny Dollo, who is presiding over the case, released Kimathi, a Kenyan, on grounds that the state had dropped charges against him. He was one of five suspects released Monday. Originally, 38 suspects were taken into custody, and that number had been trimmed to 19 before Monday.
The defendants have remained jailed on charges of terrorism, murder, attempted murder and conspiracy to commit murder.
The twin suicide bombings occurred at a popular rugby club and an Ethiopian restaurant in the Ugandan capital where people had gathered to watch the World Cup soccer finals from South Africa in July 2010. The explosions, just minutes apart, left 76 dead and scores injured.
The terrorist group Al-Shabaab claimed responsibility, saying the attacks were in response to Uganda's involvement with the African Union Mission in Somalia.
Kimathi has drawn specific attention to the case, as human rights activists have demanded his release. Human Rights Watch had issued a statement Friday demanding the Ugandan government "disclose any evidence it claims to have against the detained Kenyan human rights defender Al-Amin Kimathi or release him."
The Kenyan government also had urged Uganda to send Kimathi back to Kenya to be tried.
Kimathi's lawyer Ben Cooper told CNN that Kimathi had traveled to Uganda in his capacity as a human rights activist to "uphold law and justice" but instead had become a victim of injustice on allegations that "could not stand up."
He was arrested on September 15, 2010, in Uganda, where he had traveled to observe court hearings of Kenyan suspects in the Kampala bombings who had been transferred to Uganda. Kimathi was charged with terrorism under Uganda's Anti-terrorism Act, as well as murder and attempted murder, and was held in pre-trial detention for nearly a year.
Kimathi's brother Onesmus Mureithi Imanene was overjoyed, Cooper told CNN, and Imaneme felt his brother had been "vindicated."
Uganda says it is still under threat from extremists. Last week, the government released a fresh terror alert and reminded the public to remain vigilant at all times and report anything suspicious to police.