At least 14 soldiers were killed and several others injured in South Sudan after a suspected "love triangle" dispute led to a deadly shootout, the army said on Wednesday.

A clash between members of the Unified VIP Protection Force, which comprises government troops and opposition fighters, erupted on Monday at a market near the oil-rich Abyei Box region, which straddles the border between Sudan and South Sudan.

According to South Sudan People’s Defence Forces (SSPDF) spokesperson, Lul Ruai Koang, Monday's dispute began between two officers.

"There are two conflicting accounts regarding the cause of the crisis: first version says it was a purely personal misunderstanding between the two officers at a tea place and the other says it was a love triangle," Koang told reporters during a press briefing at the army general headquarters in the capital Juba.

Fourteen officers killed: army

"The two men reportedly quarrelled after both were reported to be romantically involved with the same lady," he said.

The situation escalated when one officer shot the other, prompting their respective bodyguards to open fire.

Violence then erupted from the market, spreading to primary checkpoints and barracks, Koang said.

"A total of 14 servicemen were killed: six from the SPLA-IO and eight from the SSPDF," Koang confirmed.

Civilian caught in crossfire

One civilian was reportedly caught in the crossfire, with their condition yet to be confirmed, while five soldiers were injured and are receiving treatment.

Koang said the incident was not "politically motivated" but confirmed that an investigation has been launched.