Syria said 23 people were killed in yesterday's protest near the Golan Heights, when Israeli troops fired on Palestinian demonstrators at the frontier fence, but the United Nations said the toll was unconfirmed.
Official news agency SANA quoted Health Minister Wael al-Halki as saying the death toll included a woman and a child, adding that another 350 people suffered gunshot wounds.
In a statement in New York, UN Secretary-General Ban Ki-moon said there were "an unconfirmed number of civilian casualties from live (Israeli) fire" and UN monitors in the area were "seeking to confirm facts".
The Israeli military offered no figures on dead and wounded, other than to say it believed that an explosion of what it said was a Syrian land mine, detonated by petrol bombs thrown by protesters, caused 10 casualties.
A Reuters reporter on the scene yesterday saw Israeli snipers firing at demonstrators and 10 people taken away on stretchers by other protesters.
Three weeks ago Israeli soldiers shot dead 13 Palestinian protesters who tried to breach Israel's frontiers with Lebanon and Syria during protests marking what Palestinians call the "catastrophe" of Israel's founding in 1948.
Yesterday's protest was held to mark the 44th anniversary of the Arab defeat in the 1967 Middle East war, when Israel captured the Golan Heights, as well as the West Bank and the Gaza Strip, where Palestinians want to establish a state.
Palestinians in Syria marched down from a hilltop overlooking the Druze village of Majdal Shams yesterday to the Israeli frontier, which before last month had been mostly peaceful for decades.
The leader of Lebanon's militant Hezbollah group, Sayyed Hassan Nasrallah, praised the "courageous" demonstrators today and said they had sent "a clear message of insistence and commitment in this umma (community)".
Israel has accused Syrian president Bashar al-Assad of allowing the Golan protests to try to divert the world's attention from his bloody suppression of the popular revolt against his authoritarian rule.
Israel is concerned that protests by unarmed demonstrators are a new tactic for Palestinians, adopted from popular revolts in the Arab world, to draw a violent response and gain more sympathy internationally for their cause.
Reuters