Responding to India's tests, and following its own nuclear tests at Ras Koh on 28 May 1998, Pakistan conducted an additional test at the Wazir Khan Khosa Test Site in the Kharan Desert. [1] Afterwards, the U.S. intelligence community disagreed over the test's yield and whether the Ras Koh device was plutonium-based. [2] No further tests have been conducted at this site.

Sources:
[1] Thalif Deen, "Defiant Pakistan Explodes Another Nuclear Device," Inter Press Service, 30 May 1998.
[2] Dana Priest, "U.S. Labs at Odds on Whether Pakistani Blast Used Plutonium," Washington Post, 17 January 1999.