Ivory Coast troops opened fire on protesters marking International Women's Day with a rally against violence in the main city of Abidjan on Tuesday, killing four.

The shooting at the rally, to protest the killing of seven women at a march last week, was blamed on rogue army officers supporting disputed President Laurent Gbagbo, according to the BBC.

A post-election standoff between Gbagbo and Alassane Ouattara — the U.N. says Ouattara won the November but Gbagbo has refused to step aside — has degenerated into urban warfare in the main city Abidjan. Northern rebels have pushed south in the heaviest fighting since they attempted toppling Gbagbo in a 2002-2003 civil war.

The bodies of three men and one woman killed Tuesday in Abidjan were seen by an Associated Press photographer inside a clinic where they were taken for treatment. 

A women's march in the Treichville neighborhood had just ended when security forces reportedly rushed into the area and began shooting.

Earlier on Tuesday, hundreds of demonstrators had gathered in the Abobo suburb near the bloodstained pavement where seven women died when Gbagbo's security forces shelled an all-women's march.

That incident provoked international outcry.

Britain's minister for Africa, Henry Bellingham, called it "a deplorable and cowardly act against unarmed protesters, calling for the results of the presidential elections to be respected". U.S. secretary of state, Hillary Clinton said: "Gbagbo and his forces have shown a callous disregard for human life."

About 300,000 people have fled their homes in Abidjan, according to the BBC, quoting the U.N. refugee agency.

Another 70,000 have fled violence in the west, seeking sanctuary across the border in Liberia.