May 27 (UPI) -- At least four Russian military personnel and several militants were killed during a battle in the eastern Syrian province of Deir al-Zour.
On Sunday, Tass, citing a defense ministry statement, said "a few mobile terrorist groups" attacked an artillery battery belonging to Syrian government forces for one hour at undisclosed time. Then, fighting erupted with the Russians.
Initially, two Russian military advisers died. Five others were wounded and taken to a Russian military hospital, where two died.
Forty-three rebels also were also killed, the ministry said.
The Syrian Observatory for Human Rights monitoring group said Islamic State fighters launched two new attacks in Deir el-Zour on Saturday near the town of Mayadeen and the town of Boukamal near the Iraqi border.
Over five days, 76 members of the regime and their Syrian and non-Syrian allies have been killed, including nine Russian soldiers, according to the rights group. And over 75 days, the death toll is more than 1,000.
Russia has lost about 90 personnel in the civil war.
Last November, Syria's army took Deir al-Zour city but Islamic State fighters are still active in the province after seven years of war. Rebel forces are mainly in Idlib.
The Syrian government, backed by Russian and Iranian military, now controls most of central Syria, including Aleppo.
One month ago, Syrian President Bashar al-Assad thanked Russian President Vladimir Putin for "saving" his country and for Russia's support in Syria. In December, Putin ordered a "significant part" of Moscow's military presence in Syria to begin withdrawing from the country.