They were reportedly planted in front of the Post Office at Area 10, Garki, Abuja.
The objects were allegedly in a parcel, wrapped and addressed to the Minister of Finance, Dr. Ngozi Okonjo-Iweala.
An eyewitness said no casualty was recorded.
Briefing reporters on the incident, the Post-Master General (PMG) of the Federation, Ibrahim Mori Baba, who said the parcel was planted last Friday by a man he described as insane, could not confirm if it was a bomb.
He said he would allow the security operatives to determine if what was defused was a bomb.
The Post-Master General said: “On Friday, a man came into the post office premises. We didn’t know whether he was sane or insane.
“He wanted to go inside the post office, but, unfortunately for him, the gate was locked. He left the so-called parcel at the main gate. I described it as so-called parcel because there are processes that have to be followed before a parcel can be accepted.
“The processes are that we will weigh the parcel and determine how much the sender will pay. We will also examine it in your presence. We will bring out the content to ensure that what you are about to send is not an explosive. The content of what you want to send will be shown.
“In this case, the man left the parcel at the gate, went inside, bought stamps and pasted them on it to indicate that the parcel has gone through the normal process. But it did not go through the normal process. The man just wanted to deceive people that he had processed it and we should deliver it. The parcel was not processed. The police came, examined the parcel and found that it was a bomb.”
Baba alleged that the parcel was addressed to the Minister of Finance, Mrs. Okonjo- Iweala