The move comes amid one of the most aggressive periods of the conflict, with Israel launching more than 140 rockets into Gaza in the last 24 hours. The additional soldiers bring Israel's total number of active reservists to 86,000.
Thursday, on the heels of an Israeli-launched strike on a U.N. school in Gaza that killed at least 15 and injured over 100 people, Israeli Prime Minister Benjamin Netanyahu promised to continue strikes against Hamas until all their underground tunnels into Israel have been destroyed.
Thus far, Israel claims it has successfully neutralized most of the 32 known tunnels; it also says it will take only a few days to finish the remainder.
"So far we have neutralized tens of terror tunnels," Netanyahu said in televised remarks at a meeting at military headquarters in Tel Aviv.
"We are determined to continue to complete this mission with or without a cease-fire ...Therefore I will not agree to any offer that does not allow the military to complete this important mission for the security of the people of Israel."