Yerevan (AFP) - Azerbaijani forces on Thursday shelled Armenia, killing three civilian women, officials in Yerevan said, as tensions mounted in the Caucasus neighbours' decades-long conflict over the disputed Nagorny Karabakh region.

Three women aged up to 94 "died as a result of shelling by Azerbaijani armed forces" in Armenia's north-eastern Tavush region close to the border with Azerbaijan, Armenia's interior ministry spokesman Ashot Agaronyan told AFP.

"A 70-year-old women was killed in the village of Paravakar village, and two other women, aged 94 and 41 were killed in the village of Berdavan. Two other civilians were wounded," he said.

"Shelling from large-calibre mortars" was still continuing on Thursday evening, Agaronyan said.

Armenia is locked in a protracted conflict with Azerbaijan over the breakaway region of Nagorny Karabakh, an ethnic Armenian enclave in Azerbaijan.

Armenia's defence ministry condemned the shelling as an "act of provocation" as the two countries' foreign ministers are set to meet on the sidelines of the United Nations General Assembly on a date still to be confirmed.

"Our neighbour's military leadership shows complete disdain towards diplomatic efforts aimed at finding a negotiated solution to the (Karabakh) conflict," Armenia said in a statement.

"Armenia will take appropriate steps to pacify Azerbaijani armed forces," the ministry added.

The two ex-Soviet nations regularly exchange fire along their shared border and across Karabakh's volatile frontline but last year clashes hit a new high.

Ethnic Armenian separatists backed by Yerevan seized control of the territory during a 1990s war that left some 30,000 dead.

Despite years of negotiations, the two countries have not signed a final peace deal to cement a tenuous 1994 ceasefire.

Energy-rich Azerbaijan, whose military spending exceeds Armenia's entire state budget, has threatened to take back the breakaway region by force if negotiations fail to yield results.

Armenia -- backed by Russia which sells weapons to both Baku and Yerevan -- says it could crush any offensive.