Four Palestinians were killed and scores wounded during an Israeli army incursion into the centre of the West Bank city of Ramallah, medical and security sources said.
The four were identified by medics as Milad Abu al-Arayes, Jaafar Ahmed, Ghaleb Abdelqader and Ayssar al-Qassem, who was a member of the Palestinian security forces.
Around 60 other people were wounded in the operation which resulted in the arrest of a senior member of the extremist Islamic Jihad group, Mohammed al-Shubaki.
Shubaki is the commander of Jihad in the Qalqilya area of the northern West Bank. Jihad has been behind all the most recent suicide attacks inside Israel.
More than a dozen armoured vehicles took part in the incursion into the centre of Ramallah which serves as the political headquarters of the Palestinian Authority, witnesses and security sources said.
According to Palestinian security sources, the Israeli forces had entered Ramallah in order to provide back-up for a unit of elite undercover soldiers who were already operating in the town.
An Israeli army spokesman said the forces opened fire only after they came under attack from gunmen.
The latest deaths bring the overall toll since the September 2000 start of the Palestinian uprising to 5,064.