A ceasefire agreement came into force at 9 a.m. local time (0500 GMT), according to media reports and a source, who asked not to be named. But Azerbaijani media reported that it was broken soon after.
Tensions flared overnight in the latest escalation of decades-old hostilities between the two countries in the south Caucasus over control of the disputed region.
Each side blamed the other for the fighting.
Conflict first broke out in the late 1980s, when both sides were under Soviet rule and Armenian forces captured swathes of territory near Karabakh, long recognized internationally as Azerbaijan’s territory. About 30,000 people died in the ensuing conflict.
Azerbaijan regained those territories in the 2020 fighting, which ended with a Russian-brokered truce and thousands of residents returning to homes from which they had fled. More than 6,500 people lost their lives in the six-week war.
The leaders of both countries have since met several times to hammer out a treaty intended to establish a lasting peace.
During EU-mediated talks in Brussels in May and April, Azerbaijani President Ilham Aliyev and Armenian Prime Minister Nikol Pashinyan agreed to “advance discussions” on a future peace treaty.
Pashinyan on Tuesday held separate phone calls with Russian President Vladimir Putin and French President Emmanuel Macron on the latest clashes, according to the Armenian government.
ZZ/PR