(CNN) -- A decade after British aid worker Charlotte Wilson was killed along with 21 others while on a bus ride in Burundi, Amnesty International and Wilson's family are still pushing the Burundi government for a full investigation of her death.
Wilson's brother, Richard Wilson, is launching a 24-hour "Twitter-a-thon" to call on the government to take action, according to Amnesty International. The "Twitter-a-thon" will start at 1.30 p.m. Tuesday -- the 10-year anniversary of the massacre.
The Titanic Express bus was traveling from Rwandan capital of Kigali to the Burundi capital of Bujumbura. The bus was attacked, and its passengers were separated by ethnicity, according to a statement from Amnesty International. The Hutus were released, while the Tutsis -- along with 27-year-old Charlotte Wilson -- were killed.
Burundian authorities and other organizations have attributed responsibility to the armed opposition group Palipehutu-National Liberation Forces (Palipehutu-FNL). The FNL has denied involvement. Ten years after the attack, no one has been brought to justice, according to Amnesty International.
"Tragically, those responsible for Charlotte's murder have killed many more innocent people over the last 10 years, while countless others have died in reprisal attacks, highlighting the deadly consequences of Burundi's culture of impunity," Richard Wilson said. "The Burundians we know tell us that justice can help end the cycle of violence."
The Titanic Express massacre was among a series of mass killings during the Burundian civil war, which started in 1993, Amnesty International said. Thousands were killed during the conflict, the organization said.
"The crimes that occurred during Burundi's civil war were extremely grave," Amnesty International UK Director Kate Allen said. "The government must respect international law and ensure that no amnesty is passed for these crimes."