Following a year of fighting after Hamas's unprecedented October 7 attack on Israel, large swathes of Gaza have been reduced to rubble as the Israeli army aimed to completely destroy the militant group.

But in recent months, troops have returned to several areas across the Palestinian territory where they had previously conducted operations against Hamas, only to find militants regrouping.

"The troops of the 401st Brigade and the 460th Brigade have successfully encircled the area and are currently continuing to operate in the area," the military said in a statement on Sunday.

It cited intelligence suggesting the "presence of terrorists and terror infrastructure in the area of Jabaliya... as well as efforts by Hamas to rebuild its operational capabilities in the area".

"Prior to and during the operation, the IAF (air force) struck dozens of military targets in the area to assist IDF (army) ground troops," the military said, adding that targets hit were weapons storage facilities, underground infrastructure sites and other militant sites.

Hamas-run Gaza's civil defence spokesman Mahmud Bassal said multiple strikes rocked Jabaliya overnight, with many casualties.

- Evacuation routes -

Residents said the Israeli military had targeted the area with heavy bombardments.

"The shelling is random and violent in multiple directions and we do not know where the shelling is coming from and we do not know where to go," Gaza resident Jameel Al Habibi told AFP.

Israeli forces have regularly targeted Jabaliya since the Gaza war began, displacing most residents.

The military said it was also expanding the humanitarian area in Al-Mawasi along the coastline in southern Gaza.

"For this purpose, two humanitarian evacuation routes from northern Gaza have been reopened: one along the Salaheddine road and the other along the Al-Rashid coastal road," the military said.

Gaza's civil defence agency meanwhile said an Israeli air strike on a mosque-turned-shelter on Sunday in central Deir al-Balah killed 26 people. Israel's military said it had targeted Hamas militants.

"The number of martyrs brought to hospitals as a result of the occupation's targeting of displaced people in the Ibn Rushd school and Al Aqsa Martyrs mosque reached 26, with several more wounded," a health ministry statement said.

Israel's military said it had "conducted a precise strike on Hamas terrorists who were operating within a command and control centre" at the mosque.

The war in Gaza broke out after Hamas militants attacked Israel on October 7, which resulted in the deaths of 1,205 people, most of them civilians, according to an AFP tally based on official Israeli figures.

The militants also seized 251 hostages, 97 of whom are still held captive in Gaza, including 33 the Israeli military says are dead.

Israel launched a blistering military campaign in Gaza, vowing to destroy Hamas and bring back the hostages.

At least 41,825 people have been killed in Gaza, the majority of them civilians, the territory's health ministry said Sunday.

The UN has acknowledged the figures to be reliable.