Fighting rages in Nagorno-Karabakh

Fighting raged around the disputed region of Nagorno-Karabakh, with Azerbaijan saying three of its troops have been killed in the past 24 hours and the Armenian president warning that the hostilities could slide into a large-scale war.

Armenian President Serzh Sargsyan warned on Monday that his country could formalise its ties with Nagorno-Karabakh by officially recognising its independence if the fighting escalates. He warned that the escalation of hostilities could lead to a "large-scale war."

The outbreak of hostilities that erupted on Saturday is the worst since a war that ended in 1994, leaving Nagorno-Karabakh under the control of local ethnic Armenian forces and the Armenian military.

Hikmet Hajiyev, a spokesman for Azerbaijan's Foreign Ministry, told Al Jazeera on Monday that Armenian forces continue to shell residential areas despite a unilateral cease-fire announced by Baku.

"For more than 20 years we have had a ceasefire and the ceasefire was always relative. But in such a situation like yesterday Azerbaijani armed forces declared that we are holding all counter measures but the Armenian side are still attacking Azerbaijan civilians. 

"In such circumstance Azerbaijan armed forces are compelled to take all necessary precautionary measures to guarantee the security of Azerbaijan civilians, and also to deter Armenia from further acts of aggression and provocation - therefor all responsibility lies on the republic of Armenia for taking such kind of provocative steps," Hajiyev told Al Jazeera over the phone from Baku.

Artsrun Ovannisian, the Armenian Defence Ministry spokesman, said on Monday that the Karabakh militia advanced overnight, "liberating new positions." He claimed that the Armenian artillery hit Azerbaijani units as they were moving to the frontline.

Armenian forces also occupy several areas outside Nagorno-Karabakh proper.

International efforts to settle the conflict, fueled by long-simmering tensions between Christian Armenians and mostly Muslim Azeris, have brought no results.

At least 30 troops and a boy were killed on both sides on Saturday as the warring parties used heavy artillery and rocket systems.

Self-proclaimed officials in Karabakh said fighting intensified in the morning in the southeast and northeast with the Azerbaijani troops using Grad multiple rocket launchers.

In Moscow, President Vladimir Putin's spokesman Dmitry Peskov said the Kremlin was "seriously worried" about the continuing fighting in the region and added that Russia will continue its efforts to ensure a cease-fire.