At least 22 people have been killed in three days of fighting in a town in the southeastern Central African Republic, a member of parliament from the area and a local journalist said on Friday.

Axar.az reports citing Reuters.

The clashes between armed Fulani herders and militia fighters in Zemio, about 1,000 km (620 miles) east of the capital Bangui, began on Wednesday. Heavy gunfire continued the following day and into Friday.

Thousands have died and a fifth of Central Africans have fled their homes in a conflict that broke out after mainly Muslim Seleka rebels ousted President Francois Bozize in 2013, provoking a backlash from Christian anti-balaka militias.

The trigger for this week's violence was not immediately clear. The Fulani herders involved in the fighting were believed to be associated with the Union for Peace in the Central African Republic (UPC), a group that belonged to the now disbanded Seleka coalition and which some experts say could be taking advantage of a security vacuum in the region.

"Already on June 28 there were 22 dead, but things have evolved through yesterday and there are several other people burnt inside houses where it's not possible to have access," lawmaker Dalou Wamboli told.

Wamboli was speaking in Bangui but had remained in contact with constituents in Zemio during the violence until telephone connections were cut. He then reached residents who fled to neighbouring towns with phone access.

Albert Stanislas Koumbobacko, a journalist from Zemio who was also in contact via phone with residents who fled, confirmed the death toll of 22.

The U.N. refugee agency (UNHCR) said on Friday that around 1,000 people had fled this week's violence.

"Many are seeking refuge in a Catholic church in the town, while some 66 people have sought safety in the UNHCR compound – among them terrified women and children in fear of their lives," it said in a statement.

A spokesman for the U.N. peacekeeping mission, MINUSCA, confirmed the clashes and said it had sent additional troops to the area but had no information on casualties.

Thirteen of Central African Republic's 14 armed groups signed a peace deal this month calling for a ceasefire, but violence has continued.

In addition to homegrown armed groups, the country has for decades held rebels from Chad, Sudan and the Democratic Republic of Congo.

Ugandan troops, backed by U.S. special forces, were deployed to the south-east to track members of the Ugandan Lord's Resistance Army, a cult-like rebel group headed by Joseph Kony, who is wanted by the International Criminal Court.

Those forces are withdrawing, however, which some observers fear will create a security vacuum. Ugandan troops pulled out of Zemio earlier this year.

"We were concerned the withdrawal would embolden Seleka fighters to move into areas they once feared to tread," Lewis Mudge, Africa researcher with Human Rights Watch, told Reuters. "The conflict has arrived in Zemio and it very well could spread to towns that, until now, had been spared."