Emotions run high on Friday in Lebanon's biggest Palestinian refugee camp, Ain el Hilweh, as thousands march in protest at the ongoing Israeli attacks on Gaza.

The protesters began their demonstration after Friday prayers, chanting slogans against Israel.

Dozens of Palestinian gunmen participated in the march.

Like many there, refugee Issam al Masri said that he came to support his brothers in Gaza, and that he hopes to one day see a liberated Palestine.

In a separate protest in Beirut, dozens gathered in front of the United Nations headquarters, denouncing the Israeli offensive and calling on Arab countries to support Palestinians.

Israel launched the offensive in Gaza on Wednesday, killing the military commander of Hamas in an airstrike.

At least 21 Gazans have died in the attacks since then, while three Israelis were killed by Gazan rocket fire on Thursday.