The chief of the Israeli army says that the military is preparing for a possible ground operation in Lebanon.
Earlier, the military said it is activating reserve troops in response to rising tensions with the Hezbollah militant group.
It came as the United Nations said more than 90,000 people have been displaced by five days of Israeli strikes on Lebanon.
The UN Office for the Co-ordination of Humanitarian Affairs said on Wednesday that a total of 200,000 people have been displaced in Lebanon since Hezbollah began firing rockets into northern Israel nearly a year ago, drawing Israeli retaliation.
The Israeli military announcement on Wednesday indicates that Israel is planning even tougher action against Lebanese group Hezbollah.
It followed Hezbollah firing a missile towards Tel Aviv for the first time.
Addressing troops on the northern border, Chief of Staff Lt Gen Herzi Halevi said the latest Israeli airstrikes were designed to “prepare the ground for your possible entry and to continue degrading Hezbollah”.
In an apparent reference to the missile aimed at Tel Aviv, he said: “Today, Hezbollah expanded its range of fire, and later today, they will receive a very strong response. Prepare yourselves.”
To achieve the goal of returning the displaced citizens of northern Israel to their homes, “we are preparing the process of a manoeuvre,” he said.
The army said it was calling up “two reserve brigades for operational missions in the northern arena”.
“This will enable the continuation of combat against the Hezbollah terrorist organisation,” it said.
The launch of the Hezbollah missile towards Tel Aviv ratcheted up hostilities in the region, even as Israel continues to battle Hamas in the Gaza Strip. There were no reports of casualties or damage.
The military said it struck the site in southern Lebanon where the missile was launched.
Israeli strikes on Wednesday killed 51 people and injured more than 220, according to Lebanon’s health minister.
The count comes in addition to 564 who were killed and more than 1,800 wounded in the previous two days, including around 150 women and children.
This week has been the deadliest in Lebanon since the bruising monthlong war between Israel and Hezbollah in 2006.
Fleeing families have flocked to Beirut and the coastal city of Sidon, sleeping in schools turned into shelters, as well as in cars, parks and along the beach. Some sought to leave the country, causing a traffic jam at the border with Syria.