Israeli commandos killed nine Palestinians, including an elderly woman, and wounded 12 others during clashes with gunmen on Thursday in a flashpoint town in the occupied West Bank, witnesses and medics said.

The Israeli military said it sent special forces into Jenin to detain members of the Islamic Jihad suspected of having carried out and planning “multiple major terror attacks”, shooting several of them after they opened fire.

Islamic Jihad confirmed battling the Israeli forces as they carried out the unusually deep raid into Jenin’s refugee camp, a militant bastion. Another Islamist group, Hamas, said its men also took part in the fighting.

The death toll — the highest in Jenin in years — drew a warning from Islamic Jihad that its truce with Israel, called after a brief exchange of fire across the Gaza Strip border last year, could be in danger. “We contacted the mediators and told them that what is happening in Jenin is an Israeli war against the Palestinian people and that it doesn’t stop at Jenin. If it continues it might not be limited to Jenin,” an Islamic Jihad official said.

At the entrances to the camp’s cramped alleyways, local youths threw rocks at army vehicles. Gunfire echoed as well as occasional explosions as militants set off improvised bombs.

As the troops withdrew and the smoke and tear gas cleared, civilians who had kept away streamed into the camp to check on casualties. A two-storey building that had been the focus of the fighting was left with heavy damage.

There were no Israeli casualties. At least one Palestinian was detained during the raid, the military statement said.

Jenin is an area of the northern West Bank where Israel has intensified raids over the past year after local men carried out street attacks in its cities. The violence has further clouded long-stalled US-sponsored talks on Palestinians statehood.

The stalemate has also rallied Palestinian support for Hamas and Islamic Jihad, which refuse co-existence with Israel — where Prime Minister Netanyahu’s government includes members opposed to Palestinian statehood.