Instructions: Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.
Input: Context : The Banja Luka incident on 28 February 1994, was an incident in which six Republika Srpska Air Force J-21 Jastreb single-seat light attack jets were engaged, and four of them shot down, by United States Air Force F-16 fighters southwest of Banja Luka, Bosnia and Herzegovina.
Answer : 28 February 1994
Output:
On what date did Banja Luka incident occur?