Israeli occupation soldiers opened fire at a vehicle carrying Muhammad Ubaid, 30, on a road between the villages of Anza and Sanur near Jenin, Aljazeera's correspondent reported on Tuesday. Ubaid was killed.
The second activist, also a member of the Brigades, is an unidentified 25-year-old man. He was injured and detained.
The group is an armed wing of Palestinian President Yasir Arafat's Fatah movement.
Aqsa Martyrs Brigades activist Nidal Ukasha was killed in an ambush by the Israeli army in al-Yasmina district of the West Bank city of Nablus, reported Aljazeera's correspondent.
Israeli forces withdrew from the area after clashing with resistance fighters and arresting five Palestinians, said the correspondent.