Egypt's army imposed an overnight curfew around the defence ministry in Cairo on Friday after protesters clashed with troops there during demonstrations against the country's military rulers, leaving one soldier dead and 373 people wounded.

The crowd hurled projectiles and insults at the soldiers sent to defend the ministry after 11 people were killed in fighting there on Wednesday, and called for the overthrow of the head of the ruling army council, Field Marshal Hussein Tantawi.

The army fired back water cannon, then teargas, and riot police surged towards the crowd with batons. Scores of wounded protesters were taken away on motorcycles and dozens of soldiers were injured.

'Field Marshal, leave! The people are dangerous!' shouted the crowds. 'Raise your voice! Our revolution will not die!'

The street violence comes less than three weeks before an election that represents the first chance for Egyptians to choose their leader freely. A successful vote would mark the most important step in a messy transition to democracy since the overthrow of autocratic leader Hosni Mubarak 15 months ago.

Last-minute changes to the line-up of contenders, bickering over a new constitution and suspicion that the military will continue wielding power after a new president is chosen are making for a chaotic backdrop to the campaign.

The troops pressed forward when protesters began cutting through barbed wire used to seal off the ministry building in Cairo's central Abbasiya district.

Protesters ripped down a metal fence at an underground railway construction site to build a barricade. Some cried 'God is Greatest' as army helicopters swooped overhead.

The teargas scattered the crowd far down the rock-strewn streets. Troops blocked off several streets between Abbasiya and central Cairo using armoured personnel carriers and some fired shots in the air.

An army conscript died from a bullet wound to the stomach, the health ministry said in a statement carried by the state news agency MENA. Injuries suffered by others included teargas inhalation and cuts and bruises, some serious.

'The crowd is coming here with sharp weapons. We have batons and water cannon and teargas to disperse them,' said one commander. 'Some of them believe if they kill a soldier they will go to heaven. What do you expect us to do?'

The authorities detained more than 170 people for attacking troops and army officers, the website of the state-owned newspaper Al-Ahram reported.

The public prosecutor also ordered the arrest of people suspected of inciting an earlier sit-in at the ministry, among them some well known personalities, Al-Ahram said, without giving their names.

As dusk approached, gunfire rang out from the top of a mosque in Abbasiya. Army special forces climbed the minaret, brought down 10 people and drove them away.

The pro-democracy Sixth of April Youth movement said on its Facebook page its followers were withdrawing from the Abbasiya area because of the bloodshed.

Protesters regrouped closer to the town centre after dark, waiting to return to the defence ministry, and some threw rocks and stones at troops blocking their path, state media reported.

The one-night curfew will last from 11 p.m. local time (2100 GMT) to 7 a.m. on Saturday, the military council said in a statement read out on state television.

The army 'calls on all citizens to adhere to this or the military will confront with determination those who try to violate it,' it said, vowing legal action against those responsible for the unrest.

Some election candidates suspended their campaigns on Wednesday after unidentified assailants fired at protesters camping near the defence ministry, starting clashes that the security forces seemed unable or unwilling to quell.

Many of those protesters were hardline Salafi Islamists upset that their candidate was ruled out of the vote, which begins on May 23 and 24 with a run-off in June.

The Muslim Brotherhood, which dominates parliament, saw its first choice disqualified too, handing a potential advantage to Mubarak-era contenders such as former foreign minister Amr Moussa and ex-prime minister Ahmed Shafiq.

Some Egyptians see the last-minute changes to the candidate line-up as proof the generals are trying to manipulate the vote.

'Remnants of Mubarak's regime are not eligible to assume any power,' Hashem Islam, a sheikh from Egypt's highest authority of Sunni Islam, Al-Azhar, told protesters at the defence ministry.-Reuters