Advanced medium range air-to-air missiles
Advanced medium range air-to-air missiles, identical to the one accidentally fired in Estonia, are pictured in service with US forces
Estonia has halted a NATO aerial military drill in the Baltic country bordering Russia after a missile was accidentally shot by a Spanish fighter jet this week.

Estonia's Defense Minister Juri Luik said that the air-to-air missile was erroneously launched Tuesday in its southern region near the border with Russia.

Estonia, a tiny member of the West's North Atlantic Treaty Organization (NATO) with 1.3 million population, says it yet unclear why the missile was misfired.

Luik added that the missile had not been found anywhere, but there were no reports of casualties.

The AMRAAM-type missile has a range of up to 100 kilometers and may have crashed into a remote nature reserve in the eastern Jogeva region not far from Estonia's border with Russia or triggered its built-in self-destruct mode and exploded in midair, Luik said.

"The Spanish defense minister has apologized and expressed deep regret," Luik said on Thursday at a news conference in Tallinn, adding that the commander of the Spanish Armed Forces had apologized as well.

Luik said he urged Spain to conduct a thorough investigation into the incident, adding he also launched a separate internal probe to review the safety regulations of arranging military air exercises.

Until the completion of that review Luik said "I have suspended all NATO exercises in the Estonian airspace."

The Eurofighter Typhoon of the Spanish Air Force was part of NATO's Baltic air-policing mission based in Lithuania and was carrying air-to-air missiles containing up to 10 kilograms of explosives.

According the Spanish Defense Ministry, two Spanish Eurofighter Typhoon 2000 jets and two French Mirage 2000 jets were taking part in a training exercise over southwestern Estonia on Tuesday, when one of the Spanish planes accidentally launched the air-to-air missile.

All the jets then safely returned to their Siauliai air base in Lithuania, the ministry said, adding that it had opened its own an investigation into the incident.

In the meantime, the Estonian government said in a statement on Wednesday the Prime Minister Juri Ratas had spoken about the incident to NATO Secretary General Jens Stoltenberg.

Ratas described the incident "horrible" and "regrettable."

"I told the secretary general of NATO that it is a serious incident and we are understandably concerned about this in Estonia. Thank God that, as far as we know, no one was hurt as a result of the incident," Ratas said in the statement.

"I asked Jens Stoltenberg to take yesterday's incident very seriously and promptly identify the circumstances," Ratas said.

However, he nevertheless praised the NATO mission as a "very important and necessary part of ensuring Estonia's security."

Russia has been critical of NATO members for posing a security threat to the country.

Foreign Minister Sergey Lavrov criticized NATO, and the United States, for the alliance's expansion towards Russia.

Lavrov said any military activity near Russian borders posed a security threat to Russia by NATO states comprising of Western European countries.

Moscow urged the alliance to respect bilateral security agreements.