About 3000 Hamas supporters gathered in Gaza City late on Saturday in a show of support for Yasin who narrowly escaped an Israeli air attack earlier in the day.
Many carried portraits of Yasin while chanting slogans against the Israeli government and its prime minister, Ariel Sharon.
In Lebanon, after the evening prayers at the Burj al-Barajneh Palestinian refugee camp in Beirut's suburbs, dozens of Hamas followers staged a demonstration to protest aginst Israel's attempt.
Men shouted anti-Israeli slogans, women carried portraits of the Hamas spiritual leader while children distributed candies to celebrate Yasin's escape.
In northern Lebanon, two separate demonstrations took place in the Nahr al-Bared and Beddawi refugee camps where residents raised portraits of Yasin, Palestinian President Yasir Arafat as well as Palestinian flags.
Arafat sent his best regards to Yasin and congratulated Haniya for escaping the Israeli air strike.
"Israel has crossed all red lines and they have opened the gates for a large escalation. This aggression will lead to a new turn of events that nobody can predict for the time being"
Usama Hamdan, Hamas representative in Lebanon
"President Arafat called to check on Haniya’s health and congratulate him on his safety," one source said, adding "He also sent his best regards to Shaikh Yasin."
In Beirut, a senior Hamas official vowed that his group would react to Israel's assassination attempt.
"The Palestinian people cannot remain silent to such aggressions," Usama Hamdan, Hamas' representative in Lebanon said.
"Israel has crossed all red lines and they have opened the gates for a large escalation. This aggression will lead to a new turn of events that nobody can predict for the time being," he warned.
"This incident has also uncovered the bias of the world which has still not denounced this aggression that also wounded 17 people, including 14 children," he said.
"He is undergoing treatment," said Hamdan who did not wish to disclose whether the wounded Yasin had been taken to hospital.