The brigades had previously been deployed on Israel's border with Lebanon. In recent weeks, however, they have been training for operations in the Gaza Strip, the IDF said on Wednesday.

"The soldiers practiced combat techniques and learned the main insights and lessons from the fighting and ground maneuver in the Gaza Strip so far," the IDF said in a statement.

At the beginning of the Gaza war more than six and a half months ago, Israel mobilised around 300,000 reservists. However, most of them have since been released.

Most recently, active troops have been deployed mainly in the Gaza Strip. Israel does not publicise its troop numbers, but a brigade usually consists of several thousand soldiers.

A Rafah ground offensive is highly controversial, as Israel's allies, including the US, its strongest supporter, have warned against this because hundreds of thousands of Palestinian refugees are in the southern city and its surroundings.

The town near the Egyptian border is considered to be the only one in the sealed-off coastal strip that is still relatively intact. Israel is planning to evacuate Rafah and wants to relocate the civilian population to safer areas such as the al-Mawasi camp.