In Tulkarem, in the northern West Bank, dozens of demonstrators waved Palestinian flags and chanted slogans against Israeli settlements and the plans, which could move ahead as soon as next month.
An AFP reporter at the scene said that Israeli forces fired stun grenades and tear gas to repel protesters approaching a military checkpoint.
"This march shows our rejection of any plan of settlement or annexation,” said Iyad Jarada, secretary of Palestinian President Mahmud Abbas’s Fateh Party in the city.
"This is our land and we will defend it with all our power and energy.”
Near Tubas, also in the northern West Bank, a protester was wounded in the head by a rubber bullet fired by Israeli forces, the Palestinian Red Crescent said.
Further protests were taking place in the West Bank cities of Ramallah, Nablus, Jericho, and the Jordan Valley, which could be annexed as part of the Israeli plan.
In the southern West Bank city of Hebron hundreds gathered, chanting against Israel’s occupation, as well as anti-American slogans.
Palestinians are vocal in their opposition to US President Donald Trump’s Middle East plan, which gives Israel the green light to annex strategic territory in the West Bank.
Such annexations would violate international law and likely inflame tensions in the volatile region.
‘Naksa’ anniversary
After more than a year of political deadlock and two inconclusive elections, Prime Minister Benjamin Netanyahu and his nearest rival Benny Gantz in April joined in a coalition government.
Under their agreement, from July 1 Netanyahu and Gantz can submit the Trump plan to their Cabinet and to parliament, with a view to endorsement.
The plan also envisions the creation of a Palestinian state, but on reduced territory and without meeting the key Palestinian demand of having its capital in East Jerusalem.
Friday’s protests coincided with the anniversary of what Palestinians call the Naksa.
"Fifty-three years of Israeli occupation today, ending it is an international responsibility,” Saeb Erekat, secretary general of the Palestine Liberation Organisation (PLO), wrote on Twitter.
More than 450,000 Israelis live in settlements deemed illegal by international law in the West Bank, where 2.7 million Palestinians live.
In the Gaza Strip, demonstrators waved Palestinians flags and held placards saying "we will recover our land”, at a rally organised by Hamas