GAZA CITY, Gaza Strip ? The soldier whose abduction sparked Israel’s invasion of Gaza is in stable condition from his wounds, a Palestinian official said Saturday, while President Mahmoud Abbas warned the coming hours were “critical, sensitive and serious” for calming the crisis.

Israeli soldiers and Palestinian militants exchanged fire for several hours in the afternoon when Israeli tanks and bulldozers crossed into Gaza and began razing farmland east of Khan Younis. No serious injuries were reported on either side.

The fighting took place north of the position Israeli troops occupied when they entered Gaza on Wednesday. The army said it was carrying out a limited operation in the Khan Younis area and the soldiers were expected to leave soon.

There had been no sign of Cpl. Gilad Shalit, 19, since he was abducted a week ago during a militant raid on an Israeli army post just outside the Gaza Strip that killed two soldiers and two of the attackers.

Ziad Abu Aen, a Palestinian deputy minister and Hamas official, said “mediators” told him Shalit had received medical treatment for wounds he suffered in the raid and was in stable condition.

The Hamas-affiliated militants holding Shalit initially said they would trade information about him for all Palestinian women and underage prisoners in Israeli jails. The militants raised their demands Saturday, calling for an end to the Israeli offensive and the release of 1,000 other prisoners in Israel, including non-Palestinian Muslims and Arabs.

The new demand appeared aimed at rallying support in the Arab world.

Israel has ruled out any compromise, saying it would only encourage more abductions.

Israel has also blamed Syria for the kidnapping, noting it gives haven to Hamas’ top leaders.