Israeli Prime Minister Benjamin Netanyahu Tuesday vowed that his government is ready to give a " very, very hard" response to an early morning Gaza militant attack against the Israeli army.

In remarks to visiting Bulgarian President Rosen Plevneliev, Netanyahu said Israel was "engaged in exchanges against terrorist aggression that comes from its southern border with Gaza ... and a whole terror network that is supporting these attacks," finger- pointing Iran as the ultimate culprit.

An Israeli Defense Forces (IDF) platoon commander sustained serious wounds in the attack, which took place as he opened a gate near Kibbutz Kissufim, adjacent to a border crossing of the same name, on border with Gaza, a Palestinian coastal enclave.

He was sent to a hospital in Beersheba, Israel Radio said.

His condition had deteriorated after reaching the hospital, the army told Xinhua.

Netanyahu charged that "Iran supported Hezbollah's terror attacks in Bulgaria and is supporting terror attacks now against us in Gaza. We will fight and we will hit them very, very hard -- very hard," the prime minister said in comments sent to Xinhua.

Five Israelis died and dozens of others wounded in a fatal suicide bombing attack on July 18 on an Israeli tourist bus at an airport in Burgas of Bulgaria.

Bulgarian Prime Minister Boyko Borissov visited Israel in early September for a series of high-level meetings, including those held with Netanyahu and Israeli President Shimon Peres.

Netanyahu, shortly after the bombing, accused Iran of perpetrating the attack, and noted a string of successful and botched attacks against Israeli and Jewish targets worldwide in recent years -- including in Kenya, Turkey, Thailand, India, Georgia and Azerbaijan.