Military attacks between Azerbaijan and Armenia 0:56
(CNN) -
Long-standing tensions between Armenia and Azerbaijan appear to have erupted in the disputed Nagorno-Karabakh region.
Both sides accuse each other of attacking civilians amid reports of casualties.
The neighboring former Soviet republics have long been at odds over territory.
This is located within the borders of Azerbaijan.
They waged a war for him that ended in 1994.
Despite the conflict ending with a negotiated ceasefire, military skirmishes between the two sides are not uncommon.
Crossing of accusations
While Armenia said it was responding to missile attacks launched by its neighbor on Sunday, Azerbaijan blamed it for the clashes.
In response to Azerbaijan's alleged missile fire, Armenian Prime Minister Nikol Pashinyan tweeted that his country had "shot down 2 helicopters and 3 UAVs, destroyed 3 tanks."
Arayik Harutyunyan, leader of the self-proclaimed Republic of Artsakh, an internationally unrecognized de facto independent Armenian state that controls Nagorno-Karabakh, said the region had lost positions to Azerbaijan.
Service members and volunteers gather in Yerevan, Armenia, on Sunday after the government imposed martial law and ordered a general military mobilization over the clashes with Azerbaijan.
LOOK
: Azerbaijan and Armenia raise tensions over the Nagorno Karabakh region
«We have lost some positions.
Mainly in the direction of Talysh and in the southern parts, ”Harutyunyan said during a press conference on Sunday.
As a result of escalating tensions, the Armenian government has decided to impose martial law and order "general mobilization," Pashinyan said in a subsequent tweet.
Martial law
On Sunday, the Azerbaijani parliament voted to impose martial law, starting at midnight (4 pm ET).
President Ilham Aliyev approved the decision.
Armenia previously claimed that its neighbor had targeted civilians in peaceful areas, including in Stepanakert, the region's capital.
Artak Beglaryan, an agent for Artsaj, said in a tweet that a mother and child had been killed.
Beglaryan also said that dozens of people had been injured and extensive damage to infrastructure had been done.
He added: "Azerbaijan is intentionally targeting civilian objects."
However, Azerbaijan suggested that Armenia was responsible for the latest outbreak between the two countries.
Hikmet Hajiyev, assistant to the President of the Republic of Azerbaijan and head of the Foreign Policy Affairs Department of the presidential administration, tweeted on Sunday: “There are reports of deaths and injuries among civilians and military personnel.
Much damage has been done to many homes and civil infrastructure. '
Azerbaijani President Ilham Aliyev speaks to the nation from the capital Baku.
'Act of aggression'
Accusing Armenia of "an act of aggression and use of force", Hajiyev added that "the political-military leadership of Armenia bears full responsibility."
At least five people from a family were killed as a result of artillery shelling by the Armenian armed forces on Sunday, according to the Azerbaijani state news agency APA, which cited the Azerbaijani attorney general's office.
So far, 19 civilians have been injured and hospitalized after the clashes, the APA reported.
LEE
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The conflict could engulf the entire area
At least 14 civilians were injured in villages along the border due to artillery and tank fire from the Armenian separatist enclave, according to state media Azertac.
CNN has not been able to independently verify the claims of either party.
"Currently, the Azerbaijani Army is taking retaliatory measures and our troops are in full control of the operational situation," the Azerbaijani Defense Ministry said in a statement on Sunday.
But the Armenian Foreign Ministry said in a statement: "We strongly condemn the aggression of the Azerbaijani military-political leadership."
"The military political leadership of Azerbaijan is fully responsible for the consequences of its aggression," the statement added.
The tension builds
The fighting between the two sides has increased in recent months.
In 2016, dozens of soldiers from both countries died during the clashes.
Two years earlier, then-UN Secretary-General Ban Ki-moon urged Armenia and Azerbaijan to "commit to immediate downsizing and continued dialogue."
This, after reports of violence and victims along the border.
The Nagorno-Karabakh region is internationally recognized as part of Azerbaijan, but is governed by a majority group of ethnic Armenians.
What Turkey says
Turkish President Recep Tayyip Erdogan expressed his support for Azerbaijan on Sunday.
And he affirmed that Armenia is "the greatest threat to peace and security in the region."
"The Turkish nation continues to support its Azerbaijani brothers and sisters with all its means, as it always has," Erdogan said on Twitter.
Meanwhile, Russian President Vladimir Putin discussed the escalation in a phone call with Armenia's Prime Minister Pashinyan, according to statements from the Kremlin and the Armenian prime minister's office.
The Kremlin statement said Putin expressed concern over the clashes.
He said: “It was pointed out that it is now important to take all necessary efforts to avoid a military escalation of the confrontation.
And, most importantly, stop military operations.
The United States said it was "alarmed" by reports of military action between Armenia and Azerbaijan.
And he urged both parties to cease hostilities immediately, according to a statement from US State Department spokesman Morgan Ortagus.
CNN's Joshua Berlinger, Arzu Geybulla, Eliott C. McLaughlin, Gul Tuysuz, Holly Yan, Hira Humayun, and Dana Ford contributed to this report.
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