Up to 400 nationalists were involved in clashes between rival crowds in the worst violence in Northern Ireland since the peace agreement was signed.
The rioting began after nationalists objected to a parade by the junior Orange Order. Petrol and paint bombs, and stones and bottles were thrown at police, and troops moved in to separate the rivals. An RUC spokesman described the unrest as "heavy rioting". The injured included a policewoman hurt when a blast bomb was thrown at RUC lines.
The crowds had gathered and grown larger as the security forces battled to keep a distance of 250 yards between them.
Hostilities first broke out in the nationalist area in the early evening and continued late into the night with the police firing plastic bullets in response to the missiles and petrol bombs thrown by the rioters.
The Garvaghy Road has been a regular point of tension between the two communities in recent years as the Orange Order has attempted to force its marches through the area.
Last night's violence is a blow to those who heralded last week's referendum in favour of a new assembly for Northern Ireland as a breakthrough.
Yesterday, pressure on the Sinn Fein President, Gerry Adams, and the Republican movement was stepped up when unionists renewed their demands for the decommissioning of weapons.
"This is a matter for Gerry Adams to deal with and he knows he is running out of time," the Ulster Unionist MP for Fermanagh and South Tyrone, Ken Maginnis, said.
Under the terms of the Good Friday peace agreement the British and Irish governments must have weapons decommissioning schemes in place by the end of June in the first stage of moves to have all paramilitary groups relinquish their weapons over the next two years.
Last night it emerged that Gerry Adams and his chief negotiator in Sinn Fein, Martin McGuinness - both alleged to have been senior members of the IRA - are to attend a garden party where the guest of honour is to be the Prince of Wales.
They have been invited to the social occasion at Hillsborough Castle this week as MPs by Mo Mowlam, Secretary of State for Northern Ireland.
Around 1,000 people will attend the event. Prince Charles, whose uncle Lord Mountbatten was murdered by the IRA, may not meet the Sinn Fein leaders. If he does, Northern Ireland sources insist his manner will be "perfectly civilised, whatever his own private views may be".
The Prince and Princess of Wales were the targets of a 1981 IRA plot to bomb a London theatre, a former IRA terrorist turned police informer alleged in a Dublin court earlier this month.
Conservative backbenchers and hardline unionists expressed their outrage at the invitations, but the Northern Ireland Office said it was "normal practice" to invite elected representatives to the annual gathering.