IDF soldiers have arrested Ahmad a-Saadi, the uncle of Ra'ad Hazem, who killed three people in a terror attack in Tel Aviv two weeks ago, Ynet reported.
Israeli forces are still searching for Hazem's father Fathi, who is wanted for inciting Palestinians against Israel, the report said.
After Ra'ad was killed by security forces, Fathi spoke to hundreds of Palestinians who had gathered outside his home to comfort him, saying "You will see victory and change in the years to come."
The Ynet report added that following Fathi's comments, he went into hiding with his other son, fearing that Israeli authorities would seek him for questioning.
Fathi had previously served as the commander of Palestinian National Security in Nablus, equivalent to a brigadier-general in the IDF. However, he retired after developing a reputation as an unstable man who had frequent disagreements, Ynet said.
Although the IDF has an interest in apprehending Fathi and his son, they are not a top priority of the security forces, the report said.