Israeli forces killed two Palestinians in the West Bank city of Nablus on Tuesday, Palestinian security sources and medical workers said.

The killings could test a truce which took effect last week between Israel and Palestinian militants in the Hamas-controlled Gaza Strip. Though the truce applies only to Gaza, attacks on militants in the occupied West Bank could trigger retaliation.

An Israeli army spokesman said troops killed a senior member of the Islamic Jihad militant group. He said he could not immediately confirm a second death.

Palestinian security sources and medical workers said one of the dead Palestinians was a member of Islamic Jihad and that the other was affiliated with Hamas.

Nablus's governor Jamal Muheisen called the Israeli raid in the city an "unjustified crime" but said he did not believe it would threaten the Gaza truce.

Palestinian forces loyal to President Mahmoud Abbas were deployed in Nablus late last year as part of a Western-backed law and order campaign coordinated with Israel.

But local Palestinian commanders say frequent Israeli raids into the city have undercut that effort.