Chadian soldiers deployed on Friday in large numbers across several districts of the capital after late-night celebrations marked the presidential election victory of junta leader General Mahamat Idriss Deby Itno.
Even before the official results gave Deby more than 61 percent in Monday's ballot, the presidential guard had parked many armoured vehicles on major junctions and thoroughfares.
AFP reporters said the number of troops on the streets Friday appeared considerably larger than after previous elections.
Just hours before the official results were announced late Thursday, Prime Minister Succes Masra had declared himself victor of the vote.
The former opposition leader appointed prime minister in January, had warned that Deby's team would rig the results to ensure he won.
Masra urged Chadians to "mobilise peacefully but firmly... to prove our victory".
The electoral commission said Masra had garnered only 18.53 percent of the vote.
Deby, 40, had been proclaimed transitional president three years ago by the army after his father, iron-fisted president Idriss Deby Itno, had been shot dead by rebels.
No stepped-up security was visible around the headquarters of Masra's Transformers' party in the south of the capital on Friday.
Soldiers had let off repeated bursts of gunfire in the air near the party HQ after the results were announced late Thursday, both in celebration of Deby's win and to deter protesters from gathering.
Heavily-armed members of the presidential guard wearing their red berets were out Friday on main roads alongside an impressive number of armoured vehicles, AFP journalists reported.
But the capital appeared calm ahead of Friday's Muslim prayers and people went about their business.
At least two teenagers were wounded by falling bullets, an AFP journalist saw.