Nairobi  - A delegation from the United Nations Security Council Tuesday visited southern Sudan amid concerns that fighting in the oil rich town of Abyei could reignite a civil war between northern and southern Sudanese forces.

Heavy fighting broke out in Abyei mid-May between Sudanese government forces and former rebels from the south, forcing tens of thousands of civilians to flee.

A ceasefire was signed, but the Sudan People's Liberation Army from the largely Christian south has accused Khartoum of building up government forces around the town.

The Security Council, led by Britain's UN Ambassador John Sawers, is hoping to defuse the crisis and cement the 2005 Comprehensive Peace Agreement, which ended a conflict that claimed over 2 million lives.

"There are serious difficulties at the moment following the very heavy violence in Abyei and the forced removal of what seems like hundreds of thousands of people from the town of Abyei who have only recently returned there," the BBC quoted Sawers as saying.

Tensions have remained high in the Abyei area since 2005 as it sits near the disputed border between the northern and southern regions and has significant oil deposits. The two sides have yet to agree on borders or a government for the region.

The delegation is also planning to address the Darfur peace process and emphasize the need for improved relations between Sudan and Chad.

Sudan and Chad are currently at loggerheads, with Khartoum accusing Chad of backing rebels from the troubled Western Darfur province.

The Security Council on Monday visited Djibouti in an attempt to bring the Somali government and opposition figures closer to a deal that would end the bloody insurgency currently wreaking havoc in Somalia.

It will also visit the Democratic Republic of Congo, Kenya and the Ivory Coast. (dpa)