Chadian presidential candidate Succes Masra's party has condemned violence against him and his supporters, urging people to defend their "will expressed at the ballot box" against electoral fraud.
Masra, a former fierce opponent of the regime before it named him prime minister, is the main challenger to military leader Mahamat Idriss Deby Itno.
The election on Monday aimed to end three years of military rule but opponents called for a boycott, dismissing it as fixed.
Masra had ramped up considerable support on the stump in recent weeks and could force a second round of voting, scheduled for June 22.
'Under surveillance'
He has also faced accusations of being a stooge by the opposition, which has been violently repressed and its main figures barred from standing.
Masra's party The Transformers said on Facebook that the 40-year-old economist was under "surveillance" and faces "threats to his safety."
The party and the political Justice and Equality Coalition which supports it also denounced "threats and serious violence" targeting their supporters as well as arbitrary arrests since Monday's vote.
It complained that access to voting stations in order to observe the count had been denied.
'Unimaginable violations'
And it said there had been "unimaginable violations, including shooting with live ammunition in order to monopolise ballots and reports of proceedings."
The Transformers party warned it did not intend to continue to "suffer in an impassive way" actions that it did not detail but attributed to "certain administrative authorities and several defence and security forces."
It urged people to "remain vigilant and mobilised to defend their will expressed at the ballot box."
According to Masra's party, his private residence is under surveillance by drone.
'Corrupted images'
"A video published online by a minister... shows corrupted images... aiming to defame him," the party said.
Official results are expected on May 21.
But The Transformers party already said Chadians have "voted massively and expressed very clearly their firm desire for change brought by" Masra.
They referred to data compiled by the candidates' teams but gave no more details.
Transition
Deby Itno and Masra faced eight other candidates who were either relatively unknown or considered not hostile to the regime.
Deby Itno was proclaimed transitional president by fellow army generals in 2021 after his father, Idriss Deby Itno, was killed in a gun battle with rebels following 30 years in power.
He promised an 18-month transition to democracy but then extended it by two years.
Opposition figures have since fled, or joined forces with Deby Itno.
Yaya Dillo Djerou's death
His chief election rival and cousin Yaya Dillo Djerou was killed in February. His party said he was shot point-blank in the head in an army assault.
The European Union on Tuesday criticised Chad's failure to allow nearly 3,000 civil society members financed by the EU to observe the presidential election.
"By so doing," the Deby-appointed electoral commission "blocked their contribution to the transparency of the electoral process financed by 3.8 million euros ($4.1 million) of European funds," the EU said on Facebook.
➤ Click here to follow our WhatsApp channel for more stories.
