Armenia’s defence ministry said Azerbaijani forces shot dead an Armenian serviceman near the two countries’ border on Monday, but Baku said the report was “a complete lie”.

The incident, if true, would mark the first such border fatality since Azerbaijan retook the region of Nagorno-Karabakh in September in a lightning military offensive that prompted the exodus of almost all the territory’s 120,000 ethnic Armenians.

Armenia’s defence ministry said in a statement that Azerbaijani forces had opened fire on Monday afternoon on an Armenian position in Bardzruni, near its border with the Azerbaijani exclave of Nakhchivan. An investigation is under way into the incident, it said, without providing further details.

Asked about the report, a spokesman for Azerbaijan’s defence ministry told Reuters the Armenian report “does not reflect the truth, it is a complete lie”.

“We categorically deny provocative information from the other side,” he said.

Border skirmishes, often fatal, are not uncommon between the two South Caucasus neighbours.

Azerbaijan’s swift recapture of Nagorno-Karabakh – which is recognised as part of Azerbaijan by the international community – has spurred concerns in some Western capitals that Baku might now try to take territory in southern Armenia with the aim of opening a corridor to Nakhchivan, the exclave which borders Turkey, Iran and Armenia.

Baku strongly denies any such intention.

Azerbaijan and Armenia have stated their wish to clinch a peace deal but have yet to agree on the demarcation of their shared border, which remains closed and highly militarised.