A Baku court jailed on Monday eight Muslim activists arrested last year after they clashed with police in a protest against a ban on the Islamic hijab for schoolgirls.

The activists were sentenced for five to six years in prison "for resisting and using violence against police, and disrupting public order", the court said in a statement.

Azerbaijani forces killed an Armenian soldier in the latest deadly clash near breakaway Nagorny Karabakh, the separatist region's defense ministry said Wednesday.

"Conscript Gor Kazaruyan, 21, was shot dead by enemy fire" on Tuesday at the Karabakh frontline's north-eastern sector, Karabakh's defense ministry said in a statement.

Azerbaijani troops killed an Armenian soldier on Saturday on the border between the two ex-Soviet enemies locked in a dispute over the region of Nagorny Karabakh, Armenia's Defense Ministry said.

"Serviceman Mger Ekhshatian, 37, was shot dead on February 9 as a result of a ceasefire violation by Azerbaijan," the ministry said in a statement.

Azerbaijan police broke up an unauthorized pro-democracy protest by opposition activists in the center of Baku on Saturday, detaining dozens of people and beating up several journalists.

Around 100 protesters briefly gathered in the capital Baku's central Fountains Square chanting "Freedom!" and demanding the dissolution of parliament and the resignation of President Ilham Aliyev.

The Vatican on Thursday opened an exhibition devoted to art treasures from oil-rich Azerbaijan -- one of the few predominantly Muslim countries with which it enjoys close ties.

President Ilham Aliyev's wife Mehriban and Cardinal Gianfranco Ravasi, head of the Vatican's Pontifical Council for Culture, inaugurated the show.

Azerbaijani forces killed an Armenian soldier on Tuesday on the border between the enemy ex-Soviet states, the Defense Ministry in Yerevan said.

"Serviceman Vaghinak Baghdasarian was killed by enemy fire," a brief Defense Ministry statement said without giving further details.

An Azerbaijani soldier who was shot by an Armenian sniper in the ex-Soviet state's remote Nakhchivan region in July has died in hospital, the defense ministry in Baku said Saturday.

The ministry said the soldier, whom it named as Rabbi Jafarov, died late Friday.

Bitter enemies Azerbaijan and Armenia traded accusations on Friday amid growing international criticism of Baku's pardoning of an extradited Azerbaijani soldier who had hacked an Armenian to death.

Ramil Safarov was pardoned, promoted and financially rewarded after being extradited to Azerbaijan from Hungary, where he had been serving a life sentence for killing the Armenian soldier with an ax during a NATO training session in 2004.

Hundreds protested outside the Hungarian consulate in Yerevan on Saturday after Budapest sent a soldier who murdered an Armenian back to his native Azerbaijan, where he was immediately pardoned.

Several hundred angry demonstrators burned the Hungarian flag and threw eggs, tomatoes and coins, accusing Budapest of doing a deal with Baku in order to profit from Azerbaijan's energy riches.

Turkey will sign Tuesday a deal with neighboring Azerbaijan on building the $7 billion Trans-Anatolian natural gas pipeline (TANAP) to carry Azeri gas to European markets, its prime minister said.

This project is about transferring the natural gas extracted from the second phase of Azerbaijan's Shah Deniz field to Europe, Prime Minister Recep Tayyip Erdogan said in a parliamentary address.