In an intelligence-based operation, Rangers on Friday claimed to have arrested five individuals in Karachi suspected for involvement in terror financing.
The paramilitary troops raided two different offices on I.I Chundrigar Road and Hockey Stadium.
According to unconfirmed media reports, both offices belong to a close aide of a political leader.
The cache of arms and ammunition recovered includes 17 Kalashnikov rifles, four pistols, nine ball bombs, and a variety of different types of ammunition.
In a separate raid, personnel from the paramilitary force raided an empty plot situated in the Baldia Town area of the metropolis.
A large quantity of arms and ammunition were recovered from the spot, claimed the Rangers spokesperson.
Following the raids, Prime Minister Nawaz Sharif called on Interior Minister Chaudhary Nisar for updates regarding the matter.
The premier is said to have also asked about the motive behind these raids.
The raid came hours ahead of the arrival of the PPP co-chairman, who returned to Pakistan after 18 months in self-imposed 'exile'.
Adviser to the Sindh Chief Minister on Information Maula Bukhsh Chandio, reacting to the raids, said the provincial government was not taken into confidence before carrying out these raids.
He criticised Chaudhary Nisar for trying to portray these raids as having some kind of relevance to the political situation in the country.
"The timing of these raids will give rise to the perception that they were politically motivated and had little to do with the [Karachi] operation," he said.