Several hundred protesters who staged an overnight demonstation in Cairo's Tahrir square after a deadly military crackdown remained in the square on Sunday after the army backed down on a threat to disperse them.

The protesters, who have barricaded the square with a burnt-out army truck, barbed wire and beams chanted against military chief Field Marshal Hussein Tantawi, who has headed the country since president Hosni Mubarak was ousted in February.

"The people demand the toppling of the field marshal," they chanted, after spending a nervous night waiting for the army to make good on its warning that it would enforce a three hour predawn curfew.

Soldiers, backed by riot police, had dispersed an overnight protest in the iconic square before dawn on Saturday, with one protester shot dead.

After the incident, the military warned that it would disperse protesters who remained in the square, keeping the demonstraters on edge throughout the night as the countdown began for the curfew.

Groups of young men would whistle and bang at barricades when they thought the military, which remained out of sight, was approaching, prompting others to run to them with sticks.

As the curfew neared its end, some protesters began to chant jokingly: "Hit us, hit us, you are taking your time and we're bored."

The military has called the protesters "outlaws" and suggested they might be led by former ruling party officials. It denied using force or live ammunition against the protesters.

Since the departure of president Hosni Mubarak, protesters have been holding regular Friday demonstrations, the last one tens of thousands strong, demanding he and other former regime officials stand trial.

Saturday's death, as troops and police stormed Tahrir to break up a previous overnight sit-in, was the first in the square since it became the focal point for 18 days of protests that triggered Mubarak's resignation on February 11.

The army denied it was responsible for the fatality, saying no deaths were discovered when it cleared the square to enforce the curfew.

It said four soldiers and nine protesters were wounded.

"Those who remain in the square will be dispersed," General Ismail Etman told reporters. But his warning was ignored by the demonstrators, who chanted slogans against the military.

"I'm not scared, I'm sad it came to this, but what right does the army have to attack us," said one protester, Mohammed Abdel Al, as he prepared to take a nap on the square.

Etman defended the military's actions the night before. "We did not use force, we did not beat anyone," he said. Any protesters hurt had been hit with stones thrown by others, he added.

For his part, General Adel Umara said that after the army cleared and left the square in the morning, a large number of "protesters came ... to Tahrir with two automatic weapons and Molotov cocktails, and they attacked three military vehicles."

He did not explain why the vehicles were left behind.

"There was a death reported, unfortunately. An initial autopsy shows it was a bullet in the mouth," the general said.

On Friday, tens of thousands had massed in the square calling for Mubarak and his lieutenants to be tried for corruption and criticising the military rulers for stalling on reforms in what was dubbed the 'Day of Trial and Cleansing'.

Tantawi, who served as the ousted president's defence minister for two of his three decades in power, has vowed to oversee a swift return to civilian rule after limited amendments to the Mubarak-era constitution were approved in a referendum last month.