MOSCOW, April 7 (Xinhua) -- The Russian Defense Ministry said Friday it will reinforce the effectiveness of the air defense system in Syria, following a U.S. missile strike on a Syrian military airfield late Thursday.
"In order to cover the most sensitive objects of the Syrian infrastructure, a set of measures will be taken in the near future to strengthen and improve the effectiveness of the air defense system of the Syrian armed forces," the ministry said in a statement.
According to the ministry, only 23 out of the 59 cruise missiles launched by the United States late Thursday (early Friday in Syria) reached the targeted Syrian military airfield in the central province of Homs, with the whereabouts of the other missiles remaining unknown.
Four Syrian servicemen were killed, two others were missing and six received burns while fighting the fire, the statement said.
Citing an unnamed source, Russia's Sputnik reported that the U.S. strike killed 10 people. No Russian citizens have been reportedly injured so far.
U.S. President Donald Trump said earlier that he had ordered the strike and the action was in the nation's "vital interest."
According to a Pentagon statement, the assault was in response to the alleged Syrian government's chemical weapons attack on Tuesday in the rebel-held town of Khan Sheikhoun. The attack killed over 70 people and wounded scores of others.
The Russian Defense Ministry, calling the accusation "groundless" and a pretext used to justify the latest U.S. action, reiterated that the Syrian troops did not use chemical weapons.
"It is clear to any specialist that the decision to launch the missile strike against Syria was made by Washington long before the events in Khan Sheikhoun settlement, which served only as a formal occasion, and the demonstration of military force is dictated exclusively for internal political reasons," the ministry said.
It stressed that Moscow is waiting for explanations from the United States on evidence of chemical weapons used by the Syrian army in Khan Sheikhoun.
Russia has suspended the memorandum of understanding on the prevention of flight safety incidents in Syria with the United States, which was signed in 2015, and called for a meeting of the UN Security Council in the wake of the U.S. missile strike, the Russian Foreign Ministry has said in a statement earlier.
"The United States, without bothering to investigate the situation, opted for a demonstration of force, and for a military opposition to a country which is fighting international terrorism," the ministry said.
It added that such a thoughtless approach only aggravates the existing problems and creates a threat to international security.
"We call upon the UN Security Council to hold an emergency meeting to discuss the situation," the ministry said.
Earlier in the day, Russian President Vladimir Putin called the U.S. missile strike an "aggression against a sovereign state" under a far-fetched pretext, saying it violates international law.
"This step by Washington is causing significant damage to Russian-U.S. relations, which are already in a deplorable state," Kremlin spokesman Dmitry Peskov was cited as saying by Russian news agency Interfax.
He added that the action is also creating a serious obstacle to the cooperation between Russia and the United States in fighting international terrorism.
The latest missile strike was the toughest direct action in Syria taken by the United States so far, increasing the risk of its confrontation with Russia and Iran.
U.S. officials said they had informed Russian forces ahead of the missile strike and that they had tried to avoid hitting Russian troops at the base, to which Moscow responded that the warnings should have been given at least 24 hours in advance instead of merely two hours beforehand.
"The U.S. missile strike fully steps outside the framework of international law and will lead only to a further escalation in Syria," Russian State Duma International Affairs Committee Chairman Leonid Slutsky said.