A fragile cease-fire in Nagorno-Karabakh appeared to be holding, despite claims of violations, as high-level meetings were held separately with the leaders of Azerbaijan and Armenia in an effort to defuse tensions.
The diplomatic scramble comes after a tenuous truce was agreed on April 5, ending three days of intense fighting between Armenian-backed separatists and Azerbaijani forces. The fighting, which has left more than 60 people dead, is the heaviest seen over the Azerbaijani territory in two decades.
Azerbaijan and Armenia fought a war over Nagorno-Karabakh from 1988 to 1994 that claimed the lives of more than 30,000 people. The conflict is generally considered to be "frozen," with internationally mediated negotiations having failed to achieve a resolution, and with sporadic violence breaking out over the years.
Russia and the United States expressed optimism as the truce went into effect on April 5, but the two warring sides were urged to return to the negotiating table.
Speaking in Berlin after talks with German Chancellor Angela Merkel on April 6, Armenian President Serzh Sarkisian urged the international community to recognize the right of Karabakh's separatists to "determine their own fate and their own future."
Chancellor Merkel, for her part, said international mediation efforts were "of the greatest urgency."
Armenian Foreign Minister Edward Nalbandian and his German counterpart, Frank-Walter Steinmeiner, also held talks.
The co-chairs of the so-called Minsk Group of mediators in the conflict -- France, Russia, and the United States -- met with Azerbaijan's President Ilham Aliyev in Baku on April 6. The mediators had "stressed that it is important to return to the political process on the basis of a sustainable cease-fire."
The conflict over Nagorno-Karabakh is also likely to loom large when Russian Foreign Minister Sergei Lavrov visits Baku on April 6-7. Russian Prime Minister Dmitry Medvedev is expected to visit the Armenian capital, Yerevan, on April 7 and also plans to visit Azerbaijan on April 8.
Also on April 6, Iranian President Hassan Rohani offered to mediate over the conflict in separate telephone conversations with his Azerbaijani and Armenian counterparts.
The truce went into effect at midday on April 5, after the chiefs of staff of the Armenian and Azerbaijani militaries reached an agreement at a meeting in Moscow to halt the fighting.
Early on the morning of April 6, Karabakh's military reported that "last night, the cease-fire was generally maintained" along the "line of contact" that effectively serves as a front line separating the combatant sides.
It added that "sporadic shooting" had taken place despite the cease-fire but that it had no impact on the general situation.
Azerbaijan’s Defense Ministry said the situation along the front line remained tense but calm. It was reported as saying on the morning of April 6 that separatist forces had "violated the cease-fire" 115 times over a 24-hour period, adding that Azerbaijani armed forces had returned fire on hostile positions.
However, it was unclear whether the allegation referred entirely to the cease-fire agreed on April 5 or the 1994 truce that stopped the war.
The ministry later said Azerbaijani positions in two areas were coming under intensive fire from Armenian mortars, which the separatists denied.
WATCH: There were scenes of devastation in the village of Talish, in Azerbaijan's breakaway region of Nagorno-Karabakh, following rocket attacks that reportedly took place before a cease-fire was declared.
Populated mainly by ethnic Armenians, the Azerbaijani territory became a source of conflict in the waning years of the Soviet Union. The situation escalated following the creation of the self-declared republic of Nagorno-Karabakh in 1991 and subsequent declaration of independence in 1992. The self-declared republic remains internationally unrecognized.
Each side has accused the other of starting the latest outbreak of violence, which has involved tanks, helicopters, and artillery.
Azerbaijan's Defense Ministry says that 31 Azerbaijani servicemen have been killed in the fighting, while one helicopter and one tank have been lost.
Karabakh’s armed forces said 29 of its soldiers had been killed and 28 others were missing in action. In addition, Armenian Defense Ministry spokesman Artsrun Hovhannisyan said two Armenian servicemen were killed in the early hours of April 6.
A number of civilians were also reported killed on both sides -- about 10 overall -- along with Armenian "volunteers."
Azerbaijan's army claims to have taken control of several strategic locations inside Armenian-controlled territory, which Armenia and the unrecognized republic deny.
On April 5 in Moscow, Russian President Vladimir Putin called the Azerbaijani and Armenian presidents after the cease-fire agreement and told them to "ensure" an end to the violence, the Kremlin said.
"It's a very nascent cease-fire, but we’re encouraged that it does seem to have taken hold," U.S. State Department spokesman Mark Toner told reporters. "We are actively engaging with both sides to urge them to strictly adhere to the cease-fire."
On an April 5 visit to a hospital in Baku where he met wounded Azerbaijani soldiers, Aliyev said the conflict could be solved peacefully if the Armenian leadership "behaves sincerely at the negotiating table."
The unrecognized Nagorno-Karabakh republic’s involvement in the negotiating process is "a priority goal," Armenian Deputy Foreign Minister Shavarsh Kocharian said on April 6. "This has no alternative."
He said the warring sides should also get back to the positions they were holding before the recent clashes.
Also on April 6, Armenian foe and NATO member Turkey weighed in to accuse Armenia of not sticking to the truce.
"I hope the steps taken by Azerbaijan to end fighting will be imitated by Armenia, but this is not the case right now," Turkish President Recep Tayyip Erdogan said.
Erdogan also accused Russia of siding with Armenia in the conflict, saying Moscow was meddling as it had in Ukraine, Georgia, and Syria.
Relations between Turkey and Russia have drastically deteriorated after Ankara downed a Russian warplane near the Syrian border in November.
With reporting by RFE/RL's Armenian and Azerbaijani services, Reuters, AFP, TASS, and Interfax