Chad says five of the soldiers were abducted then executed on Sunday, branding it a "war crime" that would "not go unpunished". CAR meanwhile says its troops were chasing rebel soldiers up to the border.

"These are war crimes that have been committed. They were premeditated. The Central African authorities must be brave to accept and admit their errors," government spokesman Abderaman Koulamallah told AFP.

He said Chad would press for an international investigation, adding: "depending on what these emissaries tell us, we will see what we can do."

The three ministers carried a letter from President Faustin Archange Touadera, spokesman of the CAR presidency Albert Yaloke Mokpeme told AFP.

The team held talks with foreign ministry officials and are due to meet Chad's junta leader, Mahamat Idriss Deby, on Wednesday.

Expressing regret for the deaths, CAR put the blame on rebels it said its soldiers had been pursuing and suggested Chad and the CAR -- "two brotherly peoples" -- hold a joint investigation.

The incident has placed the spotlight on the occasionally fraught relations between Chad -- ruled by a junta which took power just six weeks ago -- and the CAR, an unstable country battling powerful armed groups.

CAR regularly accuses its northern neighbour of supporting armed rebel groups from inside Chad.

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