A delegation of West African leaders has abandoned its trip to Mali to negotiate with the leaders of last week's coup, a source has told the BBC.The source in the Ivory Coast presidency said the leaders would now hold talks in Abidjan instead.The AFP news agency reports that the decision to turn round in mid-flight follows a protest by junta supporters on the airport runway.Mali's neighbours have already told the junta to step aside.They have placed a peacekeeping force on standby.On Wednesday, thousands took to the streets of the capital in support of the junta.Many were angry by what they saw as "foreign interference" in their country."They [the coup leaders] should stay to resolve the problems in the north, corruption and education. That is more important than elections," one protester, Khalifa Sogo, told Reuters news agency.New constitutionThe Ecowas chair, Ivory Coast President Alassane Ouattara, said that Mali's democracy could not be abandoned."We cannot allow this country endowed with such precious democratic instruments, dating back at least two decades, to leave history by regressing," Mr Ouattara said."It's why Mali needs to immediately return its democratic institutions to normal," he said.Some analysts have said that the presence of the peacekeeping force suggests that the body may be willing to use force if Capt Amadou Sanogo does not agree to step aside.The coup leaders have unveiled a new constitution as well as announcing elections in which those who took part in the coup would be barred from standing, however no date has yet been set.The coup was led by soldiers unhappy with the way Mr Toure's government had been handling a Tuareg insurgency in the north.The Tuareg rebels have forced the army out of several northern towns in recent months.Under the new constitution, a transitional committee composed of 26 members of the security forces and 15 civilians will take power.Those who serve on the committee will be given immunity from prosecution.Some of the document is similar to Mali's current constitution, including guarantees of freedom of speech, thought and movement.Ousted President Amadou Toumani Toure - widely known as ATT - said on Wednesday that he remained in the country, free and in good health."I think the most important thing today is that we should, through consensus, find a way out of this crisis. The most important thing is not ATT, not the man. What is important is democracy, our institutions, Mali," he told French radio network RF1.