(CNN) -- A mortar landed near the Russian Embassy in the Syrian capital of Damascus on Thursday, killing a Syrian civilian and injuring nine Syrian security personnel who work for the diplomatic post, Russia's foreign ministry said.
No Russians were hurt in the attack, according to the ministry, which said it was trying to determine who launched the shell.
The United States condemned the shelling.
"The United States continues to emphasize that those responsible for atrocities on all sides must be held accountable," State Department spokeswoman Jen Psaki said in a statement.
The death was one of dozens reported Thursday throughout Syria, plagued by civil war.
State-run media reported that the regime's army recaptured the city of Deir Attiya from opposition militants on Thursday. The army killed an unspecified number of militants who earlier this month had taken the city, about 50 miles northeast of Damascus, the state-run Syrian Arab News Agency reported.
The opposition group Local Coordination Committees of Syria reported at least 55 people were killed Thursday, including 20 in Damascus and its suburbs and 10 in Raqqa.
Raqqa, in northern Syria, is where a regime-fired Scud missile hit a market a day earlier, killing about 35 people and wounding dozens of others, according to the main opposition umbrella group, the Syrian National Coalition.
The Syrian conflict began in March 2011 after government forces cracked down on peaceful protesters during the Arab Spring movement. It is now a full-blown civil war.
The United Nations estimates that more than 100,000 people have died in the conflict, and 9 million have been displaced.
Syria plans to send a delegation to Switzerland early next year to participate in peace talks, but the opposition Free Syrian Army says it will pass. The United Nations announced that the often-delayed Geneva II conference aimed at ending the Syrian civil war starts January 22 in Geneva.
Geneva II is a successor to Geneva I, a June 2012 meeting in which international parties laid out a peace plan for Syria that calls for a transitional governing body. It left open the question of whether President Bashar al-Assad must leave power.
The United States and Russia announced in May that they would try to bring the warring parties to a second conference in Geneva to implement the plan. But the second Geneva conference has been delayed several times.