This thing isn’t ending until Mubarak’s either on a plane or hanging from a noose.

CAIRO (AP) — President Hosni Mubarak defied a quarter-million protesters demanding he step down immediately, announcing Tuesday he would serve out the last months of his term and “die on Egyptian soil.” He promised not to seek re-election, but that did not calm public fury as clashes erupted between his opponents and supporters.

The protesters, whose numbers multiplied more than tenfold in a single day Tuesday for their biggest rally yet, have insisted they will not end their unprecedented week-old wave of unrest until their ruler for nearly three decades goes.

Mubarak’s halfway concession — an end to his rule seven months down the road — threatened to inflame frustration and anger among protesters, who have been peaceful in recent days.

In the Mediterranean city of Alexandria, clashes erupted between several hundred protesters and government supporters soon afterward, according to footage by Al-Jazeera television. The protesters threw stones at their rivals, who wielded knives and sticks, until soldiers fired in the air and stepped in between them, said a local journalist, Hossam el-Wakil.

The speech was immediately derided by protesters in Cairo’s Tahrir Square. Watching on a giant TV, protesters booed and waved their shoes over their heads at his image in a sign of contempt. “Go, go, go! We are not leaving until he leaves,” they chanted. One man screamed, “He doesn’t want to say it, he doesn’t want to say it.”