Answer:
(Fatwa: 1370/1387=L=1430)
A land should be used in the same purpose for it was endowed; therefore erecting building on Muslim cemetery is not lawful:
قال فی الشامی: مراعاۃ غرض الواقفین واجبۃ
It was wrong from Masjid administration board to construct shopping complex, but it is allowable to perform salah in the same mosque.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
