```html

Israeli military says first stages of assault on Gaza City have begun

Attack Commences amid Regional Tensions

The Israeli military announced yesterday that the first stages of their assault on Gaza City have begun. The operation, known as "Iron Heat", is in response to ongoing rocket attacks on southern Israel by militant groups in Gaza.

Military Operation Details

According to military sources, the operation commenced with a targeted airstrike on a militant headquarters and a barrage of artillery fires. The offensive is said to be ongoing, with advancing forces reportedly making their way into the Strip.

Spokesperson Comments

"The operation is progressing according to plan and is focused on eliminating terrorist threats and stabilizing the region,"
saidLt. Col. Jonathan Conricus, an Israeli military spokesperson.

Civilian Casualties & Reactions

The offensive has reportedly caused casualties, with initial reports of 5 civilians killed and 20 others injured. The situation is ongoing and further details are emerging.

UN & International Response

The United Nations has called for an immediate cease-fire and for all parties to come to the negotiating table. The Security Council has scheduled an emergency meeting to discuss the offensive further later today.

Regional Implications & Threats

The offensive comes at a time of already heightened tensions in the region. The potential for further escalation and widespread consequences cannot be ruled out, posing an ominous threat to already vulnerable populations.