Palestinians hurl stones at Israeli troops during clashes in the West Bank village of Si’eer north of the West Bank city of Hebron October 25, 2015.

Israel has arrested more than 1,000 Palestinians and Arab Israelis since the October 1 surge in violence, the Palestinian Prisoners Club said Sunday.

Most of them were young men and women, the Ramallah-based aid group said.

The most arrests – 221 – occurred in the southern West Bank city of Hebron, a regular flashpoint where some 500 Jewish settlers live under heavy protection surrounded by nearly 200,000 Palestinians.

Next was Israeli-annexed east Jerusalem with 201, followed by the West Bank city of Ramallah with 138.

A further 160 Arab Israeli were arrested in connection with unrest, the group said.

Among the Palestinians, 87 of those arrested were placed in administrative detention, a measure which allows imprisonment without trial for six-month periods renewable indefinitely.

The club said that more than 6,000 Palestinians are currently imprisoned by Israel, 420 of them in administrative detention.

Since the start of the month 53 Palestinians and one Arab Israeli have been killed in the upsurge in violence, including alleged attackers or attempted attackers. At least eight Israelis have died.