Peter Julius Moi, who worked with the independent New Nation newspaper in Juba, was shot as he was heading home after work on Wednesday evening, his colleagues said.

Residents in the area said Moi was shot with two bullets in the back, adding that none of his belongings, including his mobile phone, had been taken.

The shooting comes just days after South Sudan President Salva Kiir (pictured above) issued a warning to reporters before flying to Ethiopia for peace talks aimed at ending more than 18 months of fighting in the world's newest nation.

"Freedom of the press does not mean you work against your country," Kiir told journalists Sunday. "If anybody among them [journalists] does not know that this country has killed people, we will demonstrate it one day, one time," he added.

US urges investigation

The United States called for a thorough investigation of Moi's death and for Kiir to renounce his comments.

"We're very concerned about this development," State Department spokesman John Kirby told reporters, speaking after Moi's death. He urged authorities in South Sudan "to expeditiously and thoroughly investigate this incident."

"Separate and distinct, we are obviously deeply concerned by President Kiir's comments regarding journalists earlier this week, and we call on him to disavow those words," Kirby added.

The Committee to Protect Journalists' East Africa representative Tom Rhodes called the killing a "very foreboding sign."

"It is still too early to tell whether there is a link [with Kiir's remarks], but this tragedy will certainly cast a pall over independent reporting in the country as South Sudanese journalists are increasingly forced to self-censor as a means of survival," Rhodes said.

Moi is the seventh journalist to be killed this year in South Sudan, which has been engulfed in civil war since December 2013 when clashes erupted following a political row between Kiir and his deputy Riek Machar. Numerous rounds of peace talks held in Addis Ababa have failed to produce a lasting agreement, while thousands of people have been killed. Earlier this week, Kiir put off signing a power-sharing deal which had already been agreed to by rebels.

se/ (Reuters, AFP)