What's suspicious about that? The FBI is a police force, equivalent to Pakistan's FIA. It is not an intelligence agency.
If there were 50 CIA offices, then I'd be worried. The FBI is a regular law enforcement agency - it is the only law enforcement agency that is allowed to operate in all of the states of the USA; whereas individual police forces can only operate within the boundaries of each state in the USA.
If Pakistan asked for help with police investigations into terrorism from the USA, such as applying the latest investigative methods and technologies, the FBI is the only agency in the USA with that expertise.
Knowing that FBI has abducted and tortured people in Pakistan, you are still saying that what is suspicious about it.