The exchange of airstrikes and rocket fire between militant groups in the Gaza Strip and the Israeli Defense Forces continued Wednesday, with the death toll rising and as the United Nation's Middle East envoy warned of "full-scale war."

Militant groups in Gaza have launched 850 rockets from the coastal enclave towards Israeli territory since Monday, in addition to 200 unsuccessful launches, while Israel has carried out around 500 bombings, according to the Israeli Defense Forces (IDF).

A military spokesman said Wednesday that the troops are acting "under the same guidelines" as in the 2014 conflict during the current escalation of violence that has now resulted in the death of 35 Palestinians, including 12 minors, and five people, including a teenager, in Israel.

In its attacks against targets of Islamist groups Hamas and Islamic Jihad, the IDF is trying to reduce "collateral damage" and "minimize" civilian casualties, he said.

So far, among those killed in the enclave are 12 children and three women, while Israel estimates that it killed at least 20 militiamen, in the worst cross-border violence in years.

During the night, the exchange of fire between Israel and Gaza did not stop. Combat aircraft carried out a second attack on a 14-story building in Gaza City, which houses the offices of spokesmen and members of the Hamas political ranks, after which al-Qassam Brigades - Hamas' military arm - launched a new burst of at least 100 rockets towards the Tel Aviv metropolitan area, and central and southern Israel.