The station house officer of the Sarhali police station, which was targeted by a rocket-propelled grenade a day ago, was shifted on Sunday, officials said.
A bomb disposal squad on Sunday defused the RPG near Harike Pattan river, they said.
The squad brought the RPG out of the Saanjh Kendra and safely took it to a place near the river located at the border of the Tarn Taran and Ferozepur districts for its disposal.
A National Investigation Agency team, which reached the spot on Saturday evening, was also carrying out its investigation by visiting the spot, they said.
The district police chief transferred SHO Parkash Singh to the crime investigation agency wing while SHO Patti police station Sukhbir Singh has been posted as the SHO of Sarhali police station, they said.
The RPG was fired at the police station, which was the second such attack in the state in the last seven months.
The projectile, fired by some unidentified people, hit the Saanjh Kendra adjoining the Sarhali police station on the Amritsar-Bathinda highway on Friday night.
There was no casualty but window panes and a portion of the wall of the building were damaged.
The police rounded up seven suspects and have been questioning them in connection with the RPG attack incident.
Director general of police Gaurav Yadav visited the site on Saturday and said according to preliminary investigation, the grenade was fired by using an RPG from the highway at 11.22 pm and it hit the Suvidha Centre of the Sarhali police station.
Yadav said that it was military-grade hardware which was suspected to have been smuggled from across the border.
"There is a clear indication that it is a strategy of the neighbouring nation to bleed India by a thousand cuts," the DGP said.
An FIR under the Unlawful Activities (Prevention) Act has been registered in connection with the incident.
The DGP had also said the cowardly attack was carried out at night as the enemy nation was feeling rattled after the seizure of huge quantities of heroin and a cache of arms and ammunition in the last one month which were sent through drones.
Following the attack, Opposition parties demanded the chief minister's resignation and said it was the "direct result" of the AAP government's "apathy" in maintaining law and order.
Earlier in May, an RPG was fired at the Punjab Police's intelligence headquarters located in Mohali.
RPG fired at Punjab police station, Pak hand suspected
Mohali a terror attack? Will let you know, says DGP
India can't afford a Punjab in unrest
Punjab cops bust 2 ISI-backed terror modules, 2 held
'Punjab police has busted 16 terror modules in 6 months'