Friends and colleagues of murdered Russian-Ukrainian journalist Pavel Sheremet on Monday demanded a fair investigation into his death during the unveiling of a memorial in Kyiv where he was killed four years ago.
The award-winning journalist known for his criticism of the Kremlin and Kyiv leaders, died when a bomb planted in his car exploded during morning rush hour on July 20 in 2016.
Five suspects were accused of carrying out the killing last year but there is growing discontent among Sheremet's supporters over the integrity of the investigation.
"We still do not know who ordered this murder and there is a great deal of doubt about the suspects," said Sevgil Musaieva, editor-in-chief of the online news outlet, Ukrainska Pravda which published Sheremet's articles.
"There is no reliable evidence they did it, and their lawyers have information that may indicate that the case was falsified," Musaieva told AFP.
Dozens of people at the unveiling laid flowers and lit candles in front of a stone monument in the form of a crumpled sheet of paper inscribed with the slain journalist's name.
Two women and three men -- all veterans of Ukraine's war with pro-Russian separatists in the east of the country -- were accused in December 2019 of carrying out the killing.
But there is increasing concern that the authorities have detained the wrong people and are taking too long to find those responsible for ordering and carrying out the bombing.
Ukrainian President Volodymyr Zelensky on Monday demanded that investigators come up with "convincing, irrefutable evidence" of the suspects' involvement in the murder.
Zelensky wrote on Facebook that "Ukrainians and the whole world" need to see "the true murderers of Pavel Sheremet and then the true organisers of this crime".
The main suspects in the case accused of planting the explosive under Sheremet's car are ex-serviceman Andriy Antonenko and Yuliya Kuzmenko who was a military medic.
The two have already spent seven months in pre-trial detention, but their lawyers and supporters say the authorities have unfairly pinned the charges on the former military personnel.
Three other suspects are not currently in detention.
The interior ministry and security services have come under fire for failing to make more headway on the case, four years after the journalist's murder.
"We join the Ukrainians who continue to demand a thorough, impartial and credible investigation," the US embassy in Ukraine said on Facebook on Monday.