An Indian was arrested along with them last night for allegedly helping them, they said.
The three Pakistani nationals had been living in the city's Kumarswamy layout under false names and had even got documents like the Aadhaar card, police said.
The Indian national has been identified as a native of Kerala, they said.
"We have arrested these four persons under various sections of passport (act), conspiracy and creation of false document and misrepresentation," city police commissioner Praveen Sood told reporters.
Police said the four had come into contact while working in Qatar. They first went to Muscat and then via Kathmandu entered Patna before reaching Bengaluru.
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