The whips, clubs, rocks, tear gas and bricks deployed on the streets of Harare against opponents of President Robert Mugabe - with an apparent special focus on whites - signals a deepening degree of desperation in the veteran leader's attempts to remain in power.
The street-fighting over the weekend, described by Britain's Foreign Office Minister for Africa, Peter Hain, as "thuggery orchestrated from on high''marked the first sustained episode of violence in long-simmering political tensions.
Until now, President Mugabe's opponents have been sworn by their leaders to non-violence; their greatest fear is the imposition of a state of emergency and the cancellation of parliamentary elections next month. Saturday's violence echoed their belief that President Mugabe wants the peaceful situation to deteriorate.
The Harare scuffles left 15 people badly injured, including a number of whites who appeared to have been slected forpunishment. The violence seemed to have been orchestrated by about 300 militants of the ruling party, some of them veterans of the war of independence, who see whites as the enemies of their freedom.
On Saturday morning, they were seen, armed with clubs and other weapons, leaving the Harare headquarters of the ruling party, the Zimbabwe African National Union - Patriotic Front (Zanu-PF), and headed for a legal demonstration by about 3,500 supporters of the National Constitutional Assembly (NCA), which is one of the leading opposition bodies. The police, who are undergoing British training, appear deliberately to have stepped back after briefly attempting to halt the NCA demonstration.
The Zanu-PF militants, who are also responsible for some 400 ongoing occupations of white-owned farms, are generally referred to as "veterans" even though many are too young to have taken part in the bush war which, 20 years ago, ended white rule in Rhodesia. To all intents and purposes, the veterans are Mr Mugabe's shock-troops - a privileged class of militants, more numerous than the national army, who receive generous pensions from the state.
The NCA supporters are generally urbanite professionals who played an important role in defeating the draft constitution that President Mugabe put to a referendum in February. The draft aimed to entrench Mr Mugabe's power by making him executive president, and called on Britain to pay compensation for land which the government would acquire for popular resettlement programmes. Britain has no intention of paying compensation - it stopped doing so in 1988 after finding that requisitioned farms were going to the Ã©lite - so the land grabs would be uncompensated.
Out of the NCA grew the Movement for Democratic Change (MDC), led by the Blairite trade union boss, Morgan Tsvangirai, and supported by industry and commercial (white) farmers. The MDC is seen by Mr Mugabe, who remains steeped in liberation war rhetoric, as a whitesupported conspiracy against the liberators, Zanu-PF.
Even though Saturday's street fights were the first in Harare since food riots in 1998, there have already been some casualties in the pre-election period. Last Friday, Edwin Gomo, an MDC supporter, died from head wounds he had sustained during a stoning incident at Bindura, northern Zimbabwe, a few days previously.
Earlier, in an apparent endorsement of claims by Mr Mugabe that the MDC isforeign-backed, two German businessmen were beaten by Zanu-PF supporters. The South Africa-based men, Peter Mielke and Ulf Hassdenteufel, were allegedly at an MDC meeting with white farmers when Zanu-PF supporters broke in. Mr Mielke, 61, is being kept alive on a ventilator in a Johannesburg hospital.
The racial aspect of the tension seems largely Zanu-PF inspired. Zimbabwe-born whites such as the Commercial Farmers Union director, David Hasluck, say they have never been so comfortable as whites in Zimbabwe as they are now. Many black Zimbabweans see the whites as kingpins in the economy. The MDC's leadership, which is black, says Mr Mugabe's use of the "race card" is a tactic to deflect attention from the favouritism afforded to Zanu-PF's Ã©lite.