US-based defence think tanks say that Israeli forces faced some of the most ferocious combat seen in the offensive on Gaza to date as Palestinian fighters defended the Jabalia refugee camp from Israel’s incursion, which began on May 11 and ended with their complete withdrawal on Friday.

Civilian infrastructure in Jabalia was converted as part of a “fortified combat complex” by the Palestinian resistance, which allowed them to quickly manoeuvre in safety through buildings without exposure to Israeli air or ground attack, according to the Institute for the Study of War (ISW) and the Critical Threats Project (CTP).

In the first week of the battle for Jabalia, Palestinian fighters were involved in 341 “operational incidents” against Israeli forces, which the ISW/CTP say was a significant increase on the roughly 100 “engagements” Palestinian armed groups were involved with against Israeli forces during the first week of the Khan Younis incursion in December.

“These points taken together reflect the degree to which Hamas and other Palestinian militias remain combat-effective in and around Jabalia. Hamas and the other militias will almost certainly resume their efforts to reconstitute there as the [Israeli] units have left,” the ISW/CTP said in their latest report.