Palestinian officials say undercover Israeli troops broke into a West Bank house in a failed arrest raid Thursday, igniting a violent protest and signaling that Israeli-Palestinian security coordination may be in trouble.

The Israeli military says some 500 Palestinians threw stones and firebombs at troops near the town of Jenin. Palestinian officials say a Palestinian was shot in the hand by army fire and an elderly woman was bitten by an army dog.

No Israeli injuries were reported.

The confrontation mirrored a violent face-off between troops and Palestinians on Tuesday, when undercover troops entered the village of Tamoun to arrest an Islamic Jihad operative.

In that case, hundreds of Palestinians hurled rocks and Molotov cocktails at troops, drawing teargas and rubber bullets in response.

Earlier Thursday, AFP reported that Israel had begun stepping up arrests in a bid to stem a Palestinian uprising from taking off.

Security officials say there has been an increase in West Bank violence since November, when Israel launched Operation Pillar of Defense to end Gazan rocket fire.

In recent years, the West Bank has been relatively calm as a result of coordination between Israel’s military and Palestinian security forces in tracking down militants.

However, Palestinian officials say Israel has stepped up unilateral actions, such as surprise arrest raids, since the Palestinians won UN recognition of a nonmember observer state of Palestine late last year.