Obeid, aged 41, was killed on Wednesday when Israeli forces "targeted individuals waiting for humanitarian assistance in the southern Gaza Strip", stated the Palestinian Football Association (PFA) in a release.
UEFA shared on X: "Farewell to Suleiman al-Obeid, the 'Palestinian Pele'. A talent who inspired countless children, even in the bleakest times."
Egyptian forward Salah responded with: "Can you clarify how he died, where, and why?"
Obeid was born in Gaza City, was married, and had five children. He represented Palestine in 24 international matches.
In October 2023, Salah urged "global leaders to unite" to facilitate humanitarian aid into Gaza to "prevent further slaughter of innocent lives".
Since the onset of the Gaza conflict, initiated by Hamas's attack on Israel in October 2023, 662 individuals from the sports and scouting sectors have lost their lives, including 321 within the football community, according to the PFA.
Salah, who was the top scorer in the Premier League last season, is set to play for Liverpool on Sunday in the Community Shield at Wembley against Crystal Palace, the traditional opening match of the English football season.