India, Aug. 12 -- A week after six Bengal tiger cubs were born at the Delhi Zoo to seven-year-old tigress Aditi, marking the largest litter in two decades, two of the cubs have failed to survive the initial period of "critical care", zoo officials said.

While the first death occurred in the zoo enclosure on Friday, the second died at the zoo hospital after developing an infection, officials said, adding that the initial few days are crucial due to a higher mortality rate.

Sanjeet Kumar, the Delhi zoo director said that of the six cubs, the first was extremely small and died on Friday, four days after its birth. Another was fairly weak and was not able to feed on the mother's milk. "It was weaned and transferred to the zoo hospital on Sa...