South Sudan's government and rebels are taking a more than two-week break from key peace talks having seemingly made little to no progress in three weeks, mediators said Tuesday.

The IGAD regional bloc, which is brokering the peace talks being held in Ethiopia, said both sides were halting the talks until March 20 in order "to further reflect and consult on guiding documents of the process".

Almost 40,000 people may have been displaced by militia arson and looting in Sudan's Darfur region, according to new data obtained by Agence France Presse on Tuesday.

More than 19,000 arrivals have been recorded at two camps for displaced people near the South Darfur state capital, Nyala, the International Organisation for Migration said.

Arson and looting by militia has displaced about 20,000 people in Sudan's Darfur, adding to the strain on agencies struggling to aid almost two million uprooted by 11 years of war.

International peacekeepers in the region said they were deeply concerned about a reported escalation of violence in South Darfur state during the past few days.

Sudanese authorities have denied international peacekeepers access to part of the troubled Darfur region where villages have been reported burned and civilians uprooted, the mission said Monday.

The restriction is the latest of many cited by the African Union-United Nations Mission in Darfur (UNAMID), despite an agreement with the government which says peacekeepers have freedom of movement.

The United States on Thursday denounced what it said was the growing use of security forces by repressive regimes to crackdown on a worldwide groundswell of pro-democracy protests.

"The fundamental struggle for dignity, for decency in the treatment of human beings... is a driving force in all of human history," Secretary of State John Kerry said as he released his department's 2013 human rights report.

Khartoum dispatched reinforcements to its front lines Thursday as government and rebel delegations gathered in the Ethiopian capital to resume talks to end fighting in Sudan's South Kordofan and Blue Nile states.

The African Union-mediated negotiations aim to end the nearly three-year-old war in the two restive states, which aid groups say has left 1.2 million people in need of humanitarian assistance.

About 100 Sudanese journalists and activists staged a silent vigil on Thursday in support of a global campaign to support Al-Jazeera television journalists detained in Egypt.

"Working as a journalist is not a crime," said a banner held by the protesters who gathered on a street near the Qatar-based satellite channel's Khartoum office.

War crimes have been committed by all sides in conflict-wracked South Sudan, Human Rights Watch said Thursday, reporting widespread atrocities in weeks of carnage in the world's youngest nation.

Thousands have been killed and almost 900,000 forced from their homes by over two months of battles between rebel and government forces, backed by troops from neighboring Uganda.

Sudanese security agents on Wednesday confiscated the weekly press run of an economic newspaper edited by a prominent government critic, the editor told Agence France Presse.

Khalid Tigani, chief editor of Elaff weekly, said the move follows recent seizures of other publications despite President Omar al-Bashir's January appeal for a political and economic "renaissance" in the country ravaged by armed insurrection, poverty and political turmoil.

The African Union said Tuesday it hopes a resumption of peace talks between Khartoum and rebels this week will lead to their joining a broader dialogue about Sudan's political future.

The AU-brokered negotiations are to resume in the Ethiopian capital Addis Ababa after a first round adjourned on February 18 without a single face-to-face meeting between the combatants.