By Nadine Awadalla

KHARTOUM (Reuters) - Sudan's opposition alliance said on Thursday the ruling military council's 72-hour suspension of talks with protesters was a "regrettable" setback to efforts to forge a new democratic era following the overthrow of veteran leader Omar al-Bashir.

Describing protesters as "increasingly angry", the alliance issued its condemnation after some of the worst violence in weeks in central Khartoum.

On Wednesday at least nine people were wounded by troops firing live ammunition to clear demonstrators. On Monday, at least four people were killed when security forces tried to clear some protest sites - the first deaths linked to the Khartoum upheaval in several weeks.

In a televised speech, the head of Sudan's Transitional Military Council (TMC), Lieutenant General Abdel Fattah al-Burhan said the council had decided to suspend talks for 72 hours "until a suitable atmosphere is created to complete an agreement".

Burhan said protesters were disrupting life in the capital by blocking roads outside a protest zone agreed upon with the military.

Protesters in recent days have sought to expand their presence beyond a sit-in outside the defense ministry that remains the center of opposition demonstrations.

On Thursday, Reuters witnessed protesters near Khartoum University manning a road block on Nile Street, a major avenue running south of the Blue Nile that is outside of the zone.

The opposition alliance, known as the Declaration of Freedom and Change Forces (DFCF), said that the military council's suspension of talks ignored demonstrators' feelings.

"The suspension of negotiations is regrettable...and ignores the reality of the revolutionaries who are increasingly angry as a result of the bloodshed and the souls that we lost," the alliance said in a statement.

MONTHS OF DEMONSTRATIONS

It promised to maintain sit-in protests outside the Defense Ministry and across the country.

The sit-in, the culmination of months of demonstrations against Bashir's three-decade rule, was not halted after the army removed him from power on April 11 as the opposition demands that the military hand over power to civilians.

The violence has cast a shadow on talks that had appeared on course to reach a deal on forming a joint military-civilian body to run the country for a three-year transition period until presidential elections.

In Nile Street, some protesters said they thought they should go back to blocking a smaller area, which includes the space outside of the defense ministry compound, where the sit-in started on April 6.

"In my opinion the barriers on Nile Street are unnecessary," said 27-year-old Yousef, a doctor, who gave only his first name.

"But some of the guys feel that if we break them down that means we are retreating which means... the old regime, or the "shadow regiments" or whatever, will expand into our areas and put pressure on us."

Another protester, Rayan al-Hadi, 25, said she would follow the instructions of protest leaders if they decided that barriers should be taken down. But she was personally in favor of keeping up the barriers on Nile Street.

"When we closed the street, we had a certain vision for escalation and we don’t want to relinquish it," Hadi said.

"The people are divided, for and against removing the barriers."

Instability in Sudan, one of the largest countries in Africa, would threaten the security and stability of a volatile region that includes the Horn of Africa, Libya and Egypt, the most populous country in the Arab world.

(Reporting by Nadine Awadalla in Khartoum and Mohamed El-Sherif in Cairo; Writing by Lena Masri, Editing by Angus MacSwan, William Maclean)