Heavy shelling of tanks and helicopters kill around 300 people in a fresh wave of violence in South Sudan despite UN calls for peace between rivals factions.
Heavy fighting erupted again in South Sudan's capital Juba on Monday despite international calls for calm after deadly gun battles sent thousands of people fleeing for safety and threatened the young nation's shaky peace.
The United Nations expressed deep alarm over the surge in violence, which has left several hundred people dead and risks plunging the country into a new civil war.
The fighting broke out on Thursday and Friday on the eve of the country's fifth anniversary of independence, between troops loyal to President Salva Kiir and soldiers who support vice president Riek Machar.
On Saturday Juba was calm, but on Sunday a witness said gunfire was heard in the Gudele and Jebel suburbs of Juba, near the military barracks that host troops loyal to Machar.A spokesman for former rebel leader turned vice president Riek Machar blamed government troops.
"Our forces have been attacked at Jebel base," said James Gatdet Dak, who claimed the attack had been repulsed. "We hope it will not escalate," he said.
The violence has raised fears South Sudan could face more instability after emerging from a two-year civil war, which began in December 2013 after Kiir sacked Machar as vice president for allegedly plotting a coup.
Intense battles resumed on Monday with tanks and helicopter gunships deployed and artillery and mortar fire heard in parts of the city.
Witnesses said "very, very heavy fighting" was taking place, with residents barricading themselves inside houses and aid workers holed up in bunkers while the US embassy warned of "serious fighting between government and opposition forces".
The UN Security Council demanded on Sunday that President Salva Kiir and his Vice President Riek Machar "do their utmost to control their respective forces, urgently end the fighting and prevent the spread of violence".
The violence marks a fresh blow to last year's peace deal which has failed to end the civil war that broke out in December 2013, when Kiir accused Machar of plotting a coup.
The war has been characterised by rape, massacres, attacks on civilians, the use of child soldiers, pillage, widespread destruction of property and displacement of the population.
The Security Council on Sunday pressed South Sudan's neighbours to help end the renewed fighting, asking for extra peacekeepers as well as demanding that Kiir and Machar rein in their forces.
It called for the two rivals to "genuinely commit themselves to the full and immediate implementation of the peace agreement, including the permanent ceasefire and redeployment of military forces from Juba."
UN Secretary General Ban Ki-moon said he was "shocked and appalled" at the violence in the world's youngest nation.
An appeal for calm by the South Sudan Council of Churches, representing the country's bishops, was played repeatedly on the radio from Sunday while a South Sudanese civil society organisation said civilians had taken shelter in churches.
"We condemn all acts of violence without exception. The time for carrying and using weapons has ended, now is the time to build a peaceful nation," the message said.
South Sudan's Information Minister Michael Makuei blamed the former rebels for the violence. A "unilateral ceasefire" which Makuei said would be ordered by Kiir failed to materialise late on Sunday.
Aid workers said a UN camp housing around 28,000 people previously uprooted by the war had been caught in the crossfire, wounding some civilians.
A steady stream of people clutching children and possessions headed for the hoped-for refuge of another UN base close to the city's airport on Sunday, only to find fighting erupting there as well. There were also reports of hundreds of South Sudanese crossing into neighbouring Uganda.
A peace agreement last August ended the war but Kiir and Machar have yet to integrate their forces, a key part of the peace deal.
The United Nations runs a camp for people uprooted by the war close to where both former rebels and government soldiers are camped.
The UN Mission in South Sudan said in a tweet that the clashes had been going on for nearly seven hours with all responsible sides proving relentless.
South Sudan has seen more fighting than peace since independence in July 2011. The August 2015 peace deal was supposed to end the conflict but fighting has continued despite the establishment of a unity government.
The African Union also issued a statement condemning the shootings in Juba and appealed for peace, according to a tweet by the UNMISS.