Date: 201603
Local time of day: 1801-2400
Location: LGA.Airport, NY
Flight conditions: VMC
Light: Night
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B NYC
ATC / advisory: TRACON N90
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Human factors: Confusion; Situational Awareness; Communication Breakdown
Second reporter function: Captain
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Airspace Structure; Procedure; Human Factors; Aircraft
Primary problem: Human Factors

Narrative: Going into the airport at night we were told to follow the river and maintain 4;000 feet. We did this. Then given a heading of 050 degrees and a descent. No problems there. Then given a base turn approximately 7 [to] 9 mile final. We were asked if we had the traffic in sight at our one o'clock. We did have THAT particular traffic in sight. We were cleared for the Visual Approach and instructed to follow the traffic at our 1 o'clock. We were about 5 miles behind him.There was also traffic at our 9:30/10 o'clock on final same altitude for the same runway. We realized were converging. We ask ATC; they say turn hard right (no heading); so we fly the plane in the manner needed to avoid the traffic and came back for an uneventful Visual Approach.


Second narrative: The weather was VFR. We were flying up the River at 4;000 feet. We were told to make a right turn heading 050 degrees which would be our base leg towards the final approach course. Upon being established air traffic control asked if we had traffic at our 1 o'clock that had already been cleared for the approach. Both the First Officer and I had the traffic in sight and we were certain based on the instructions given that it was the traffic we were told to follow.They then gave us an intercept heading to follow the traffic and cleared us for a Visual Approach. As we commenced the turn I saw there was additional traffic at our 10 o'clock. It appeared that there would not be enough separation between our aircraft and the aircraft at our 10 o'clock. After seeing it on our display I immediately asked the First Officer to query the air traffic controller and to verify if he meant for us to follow the traffic at our 10 o'clock. The air traffic controller immediately replied 'you're following the wrong traffic; make an immediate hard right turn'; with no specified heading given but we knew it was to avoid the converging traffic and break off of the approach clearance given.The traffic we followed was complying with the controller's instructions and he worded it as if we made the mistake. Although; there was no RA; had we continued it could have potentially resulted in one. I believe in this case both the First Officer and I reacted appropriately based on the situation and the air traffic controller gave the incorrect instructions. We eventually got additional vectors and landed without further incident.


Synopsis: An aircraft was issued traffic information and was instructed to follow the traffic for a Visual Approach. The aircraft sighted and followed a different aircraft than the Controller intended them to follow.