The council has chose to cancel all agreements with the protest groups and called for elections within nine months under regional and worldwide supervision, he said.
Lieutenant General Abdel Fattah al Burhan said that the coalition was equally responsible for the delay in coming to an agreement.
U.N. High Commissioner for Human Rights Michelle Bachelet said, "The protestors in Sudan have over the past few months been an inspiration, peacefully demonstrating and working to engage with the Transitional Military Council".
TRT World 's Reagan Des Vignes reports.
Protest leaders have demanded proper preparations for elections during a transitional period led by a civilian administration.
This does not bode well at all for Sudan, an Afro-Arab nation torn and traumatised by decades of civil strife, military rule and economic crises and whose leader of 29 years, general-turned-president Omar Al Bashir, was removed by the military a little under two months ago.
The military council has also been under both domestic and worldwide pressure to hand over power to civilians.
"The tents are there, and the youth are moving freely", Shamseddine Kabbashi told Sky News Arabia.
The Sudanese Journalists Network is part of an alliance of professional organizations that has led the demonstrations since April against military rule.
"The people of Sudan deserve an orderly transition, led by civilians, that can establish the conditions for free and fair elections, rather than have rushed elections imposed by the TMC's security forces", the countries said in a joint statement on Tuesday.
Outside the army headquarters "there is no one, but the pure bodies of our martyrs that it has not been possible to evacuate from the site".
Opposition-linked medics said more than 35 people were killed in the attack which was rapidly condemned by African and Western nations.
But Arab governments called for renewed talks between protesters and the military.
Representatives of the protesters had been in talks with the military over who will take control following the ousting of long-time President Omar al-Bashir.
Another resident of the area, in east Khartoum, said he had seen forces in "police uniform" trying to expel the demonstrators.
"We stand with the peaceful protesters in Sudan".
"Now the streets are closed (with barricades made) from stone and the chant is going round "Just fall, that's all, the whole Council", a witness in Port Sudan on the Red Sea said.
Britain's ambassador Irfan Siddiq said bursts of gunfire could be heard from his residence for over an hour.
"No excuse for any such attack", he wrote on Twitter.
The US assistant secretary of state for Africa, Tibor Nagy, said it was a "brutal and coordinated attack, led by the Rapid Support Forces militia, that mirrors some of the worst offences of the Bashir regime".
In response, the TMC expressed "sorrow for the way events escalated", saying that the operation had targeted "trouble makers and petty criminals".
"The protesters holding a sit-in in front of the army general command are facing a massacre in a treacherous attempt to disperse the protest", the main protest group said in a statement, urging the Sudanese people to come to their rescue.
Social media users said soldiers from the RSF, a paramilitary force led by General Mohamed Hamdan Dagalo, the military council's deputy head, were firing into the air to "terrorize" people and beating demonstrators with batons.