Thousands flocked on Wednesday to a hilltop memorial above Yerevan to mark the 98th anniversary of the mass killings of Armenians in the Ottoman Empire during World War I which Armenia wants recognized internationally as a genocide.

In the annual ceremony broadcast by all national television channels, huge crowds headed to the memorial that commemorates the massacres to lay flowers at the eternal flame.

Armenian President Serzh Sarkisian on Tuesday took oath for a second term in a grand inauguration ceremony boycotted by the opposition who defiantly held a rival event of their own.

Sarkisian won February elections in the ex-Soviet state but the second placed candidate Raffi Hovannisian alleged mass violations and still insists that he was the true victor.

Armenia's last national airline, Armavia, on Monday ceased operations and launched bankruptcy procedures due to grave financial problems, the company said.

"Over the last three years, the owner of Armavia airline has been investing finances from (his) other businesses in order to support the air carrier," Armavia 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.

Armenian President Serzh Sarkisian has won re-election with over 58 percent of the vote, official results published Tuesday showed, as his main rival cried foul.

The Central Election Commission said that tallies from all voting precincts, following Monday's election, showed former foreign minister Raffi Hovannisian trailing in a distant second place with 36.75 percent of votes cast.

Armenians voted Monday in presidential polls marked by lack of any serious challenge to incumbent President Serzh Sarkisian and shadowed by an assassination attempt against a rival candidate.

The poll will test the small Caucasus nation's democratic credentials two decades after the Soviet Union's collapse, a period defined by dangerous tensions with neighboring Azerbaijan over the region of Nagorny Karabakh.

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.

Armenia's security service said Friday it had arrested two men over a gun attack that wounded a top candidate in this month's leadership polls.

The two, 47-year-old Khachatur Pogisian and 41-year old Samvel Harutyunyan, "are suspected of committing an attack against presidential candidate Paruyr Hayrikyan," the National Security Service said in a statement.

Armenia's presidential elections are set to go ahead on schedule on February 18 after a candidate injured in an apparent assassination bid said Tuesday he would not press for a delay.

Veteran politician and Soviet-era dissident Paruyr Hayrikyan was wounded in the shooting attack last week, in a crime that rocked the political establishment in the Caucasus state.

An unknown attacker shot and wounded a prominent candidate in Armenia's presidential elections, rocking the ex-Soviet state less than three weeks before it goes to the polls, police said Friday.

Paruyr Hayrikyan, head of the Union for National Self-Determination, is one of Armenia's best known politicians and a veteran figure who was jailed in Soviet times and then exiled for his promotion of Armenian independence.