Lasers were pointed at planes flying into Leeds Bradford Airport in two separate occasions within minutes of another.
Both incidents occurred late on Monday evening at 10.25 and 11.10pm, as the planes flew over Carr Gate in Wakefield and Kirkstall in Leeds respectively.
The pilots on both aircraft reported having green lasers shone into the cockpits.
A statement was issued by police on Tuesday saying both incidents followed two similar ones last week where a green laser was shone at planes flying over Kirkstall.
Lasers can dazzle pilots flying aircraft and anyone found shining one directly at a plane faces a prison sentence.
A West Yorkshire Police spokesman said: "At 11:42pm last night police were contacted by air traffic control staff at Leeds Bradford Airport reporting two separate incidents involving aircraft over the Kirkstall area of Leeds and the Carr Gate area of Wakefield.
"At 11:10pm an approaching aircraft had reported a green laser being shone repeatedly into the cockpit, and at 10:25pm another approaching aircraft reported seeing a green laser.
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"It follows two similar incidents last week where a green laser was shone at aircraft from the Kirkstall area. Officers from the local neighbourhood policing team have been made aware and are carrying out enquiries to identify the specific location and trace those responsible.
"Shining a laser at an aircraft can dazzle and distract the pilot and those caught committing such offences can face a prison sentence.
"Anyone with any information that could assist in identifying those responsible is asked to contact officers via 101 quoting crime reference 13190424685 or call the independent charity Crimestoppers anonymously on 0800 555 111."
A spokesman for the Civil Aviation Authority, said: "Shining a laser at an aircraft in flight could pose a serious risk to flight safety and is also a specific criminal offence.
"Anyone convicted of shining a laser at an aircraft could face a significant fine or even prison. We strongly urge anyone who sees lasers being used in the vicinity of an airport to contact the police immediately."