President Says a Coup Failed in South Sudan

President Salva Kiir of South Sudan said Monday in a televised address to the nation that the military had foiled a coup.

KHARTOUM, Sudan — Soldiers loyal to the former vice president of South Sudan tried to overthrow the government, President Salva Kiir said Monday, continuing the political tension that has hung over the fledgling country for months.

At a televised news conference, Mr. Kiir, dressed in a camouflage army uniform, told the nation that a “group of soldiers” allied with the former vice president, Riek Machar, had tried to orchestrate a coup in the capital, Juba. “The attackers fled, and your forces are pursuing them. I promise you today that justice will prevail.”

In July, Mr. Kiir dismissed his entire cabinet, including Mr. Machar. The cabinet shake-up was seen in part as an attempt to ease hostilities with South Sudan’s neighbor to the north, Sudan, because some of the members were viewed as longstanding adversaries of Sudan and as obstacles to improving relations.

But a number of them were also seen as political rivals to Mr. Kiir himself. Earlier in the year, Mr. Machar had hinted at challenging Mr. Kiir for the leadership of their party before national elections in 2015.

Mr. Kiir also announced a curfew in Juba between 6 p.m. and 6 a.m. until further notice. “The government is in control of the situation,” he said.

Witnesses said gunshots could be heard in Juba on Monday evening. The American Embassy released a statement saying that it had received “reports of sporadic gunfire in parts of the city” and that “the airport in Juba is also currently not operational.”

The embassy also denied that any South Sudanese “political or military figures have taken refuge within the U.S. Embassy.”

In a statement by the United Nations Mission in South Sudan, Hilde Johnson, the secretary general’s special representative, said, “I urge all parties in the fighting to cease hostilities immediately and exercise restraint.”

In a separate statement, the United Nations said that thousands of people had sought refuge in the United Nations Mission’s compound in Juba as a result of the upheaval.

This article has been revised to reflect the following correction: