The strain between rivals Azerbaijan and Armenia over a key transit route in the disputed Karabakh region is worrying, according to Bujar Osmani, chairperson-in-office of the Organization for Security and Co-operation in Europe (OSCE).

Following separate telephone talks with Azerbaijan Foreign Minister Jeyhun Bayramov and Armenian Foreign Minister Ararat Mirzoyan on Thursday, Osmani expressed concerns about the Lachin corridor's effect on the civilian population.

Despite peace talks between Baku and Yerevan, tensions between the neighboring countries have escalated in recent months over the Lachin corridor, the only road linking Armenia to Azerbaijan's Karabakh region, which divides the ex-Soviet republics.

OSCE said Osmani talked about humanitarian considerations and people's immediate needs in the Lachin corridor.

''Osmani expressed his concerns about the situation around the Lachin corridor and the impact on the civilian population, in particular vulnerable groups, including women and children,'' OSCE said in a statement.

Azerbaijan said Sunday that Armenia attempted to conduct reconnaissance flights above the Nakhchivan Autonomous Republic and the Lachin region.

Osmani reiterated his call for constructive and productive dialogue as an avenue for sustainable solutions for the benefit of the conflict-affected population.

''The humanitarian considerations and people's immediate needs should prevail,'' said the statement, adding that Osmani offered his offices and OSCE`s tools and confidence-building measures as part of the solutions for normalizing relations and trust-building between Armenia and Azerbaijan.

Baku has been blaming Yerevan for a gridlock in peace efforts since tensions escalated in December over a checkpoint in the Lachin corridor.

The mountainous region has been at the center of a decades-long territorial dispute between the two countries. When the Soviet Union collapsed in 1991, ethnic Armenian separatists in Karabakh, internationally recognized as part of Azerbaijan, broke away from Azerbaijan resulting in the deaths of some 30,000 people.

The sides fought two wars to control Karabakh in the 1990s and again in 2020. Six weeks of fighting in autumn 2020 ended with a Russian-sponsored cease-fire that saw Armenia cede swathes of territories back to Azerbaijan it had illegally controlled for decades.

In April this year, Azerbaijan set up the border checkpoint at the entrance to its Lachin corridor, which Armenia alleged was a "blockade" of Karabakh. Tensions soaring over the move left another half a dozen killed from both sides since December.

Baku denied the claims, saying the checkpoint was installed in response to security threats from Armenia and citing the smuggling of weapons and ammunition to Azerbaijan's Karabakh region by Armenia. Earlier this month, it temporarily halted operations at the checkpoint pending an investigation into the Armenian branch of the Red Cross for taking part in the alleged smuggling of contraband.

The latest developments followed a monthslong protest by Azerbaijani environmental activists in response to illegal mining by Armenians, which Yerevan retorted to by making claims it spurred a humanitarian crisis, as well as food and fuel shortages.

Azerbaijan insisted at the time that civilian transport could go unimpeded through the Lachin corridor.

In February, the International Court of Justice (ICJ) – the U.N.’s top judicial body – had ordered Azerbaijan to ensure free movement on the road.

Besides verbal spats, there have been frequent clashes at the two countries shared border despite ongoing peace talks between Baku and Yerevan with Moscow's mediation, as well as the European Union and the United States.

Last week, an Azerbaijani official lamented the rejection by the self-proclaimed Armenian leaders in Karabakh of Baku's proposed path for shipments in the key corridor, arguing that it presented "a significant risk to achieving a peaceful resolution of disputes between Azerbaijan and Armenia and hampers the efforts of establishing lasting peace in the region."

Similarly, Azerbaijan on Monday said it intercepted an Armenian four-rotor helicopter over its military positions in Karabakh. "On Aug. 7, around 1:30 p.m. (9:30 a.m. GMT), a DJI Mavic 3 quadcopter belonging to the Armenian armed forces tried to fly over positions of the Azerbaijani Army located in... the Basarkechar district," the Azerbaijani Defense Ministry said in a statement.

Azerbaijani units detected the quadcopter and brought it down in the area using "special technical means," according to the ministry.