Access was blocked off to Bazoum's official home and offices in the presidential complex in Niamey, although there was no abnormal military deployment or sounds of gunfire in the area, and traffic was normal, an AFP journalist saw.
"It's a fit of temper by the Presidential Guard but talks are underway with the president," the source said, speaking on condition of anonymity.
"The president is fine, he's safe and sound," the source said. "He and his family are at the residence."
The reason for the guards' behaviour and what was being discussed in the talks were not given.
An MP with Bazoum's PNDS party said: "I spoke to the president and to friends who are ministers [and] they are fine."
The country's last coup occurred in February 2010, overthrowing then president Mamadou Tandja.
However, there was an attempted coup on March 31, 2021, just two days before Bazoum's inauguration, according to a security source at the time.
Ousmane Cisse, a former interior minister under a military government of transition that ran from 2010-2011, was later detained for his suspected role in the attempted coup.
A second bid to oust Bazoum occurred in March this year "while the president... was in Turkey," according to a Niger official, who said an arrest was made.
In January 2018, nine soldiers and a civilian were sentenced by a military court to jail terms ranging from five to 15 years for having attempted to topple Bazoum's predecessor, Mahamadou Issoufou, in 2015.
Those convicted included General Souleymane Salou, a former army chief of staff and a member of the junta that had forced out Tandja in 2010.
Lying in the heart of the Sahel, Niger is two-thirds desert and has a surging population of 22.4 million, driven by a birthrate averaging seven children per woman.
The country is struggling with two jihadist campaigns -- one in the southwest, which swept in from neighboring Mali in 2015, and the other in the southeast, involving jihadists based in northeastern Nigeria.