The fatalities reportedly include an elderly woman, according to Palestinian authorities.
The Palestinian health minister, Mai al-Kaila, also said that Israeli forces had used tear gas canisters at a pediatrics hospital in Jenin, causing children to choke, Al Jazeera reported.
The Israeli military confirmed that an operation was underway in Jenin on Thursday, but did not immediately provide further details.
Jenin is among areas of the northern West Bank where Israel has intensified raids over the past year, in an attempt to crackdown on growing armed Palestinian resistance.
The identities of the casualties in Jenin were not immediately clear. The Palestinian resistance movements Hamas and Islamic Jihad said their fighters were battling Israeli troops.
The number of Palestinians killed by Israeli forces during raids in the occupied West Bank and East Jerusalem al-Quds in January is now 24, including five children.
More than 170 Palestinians were killed in such raids in 2022, many of them civilians.