Ueno Zoo allowed visitors to see its two giant pandas Wednesday after keeping the public away since Sunday afternoon.
The zoo suspended public viewing because the male, Ri Ri, and female, Shin Shin, had been mating.
Zoo officials said they confirmed that the two pandas mated twice in an outdoor enclosure.
They plan to keep the two separate starting Wednesday to run pregnancy tests on Shin Shin. Pandas give birth approximately 100 days after becoming pregnant, the officials said.
Families and students on spring break lined up Wednesday morning and rushed to the panda cage as soon as the zoo opened.