Crowds brandishing Palestinian flags and placards marched through the city centre chanting "Gaza will not surrender to the tanks and bulldozers!" and "Don't fear, Gaza, we are with you!"
Israeli Arabs have staged several massive demonstrations since Israeli warplanes launched waves of air strikes on Hamas targets in the Hamas-ruled Gaza Strip last Saturday.
Medics inside Gaza say the offensive has killed at least 436 Palestinians in the past week and wounded more than 2,290.
Thousands of police deployed in Sakhnin and across northern Israel on Saturday following a number of violent protests against the Gaza operation.
Some protesters in Sakhnin called Egyptian President Hosni Mubarak a "coward" and accused him of "collaborating with the Americans."
The 1.4-million-strong Arab-Israeli community makes up about 20 percent of the country's population, and consists of the descendants of the 160,000 Palestinians who remained after the creation of Israel in 1948.