Fighting raged around the ancient Syrian city of Palmyra as Syrian forces backed by Russian air strikes battled to recapture the city from Islamic State (IS) fighters.
Fighting on March 21 took place just four kilometers from the city, which has been controlled by IS fighters since May.
Syrian troops and militia forces under the cover of Russian and Syrian warplanes have been pushing toward Palmyra, a UNESCO World Heritage Site, since early this month.
The Syrian Observatory for Human Rights (SOHR) said the Syrian government advance on the city has been "slow" despite hundreds of air strikes in the last few weeks.
IS militants have fiercely fought against the Syrian advance, killing at least 26 pro-government fighters on March 21, the SOHR reported.
The IS-linked website Aamaq claimed that a jihadist suicide bomber had killed 30 troops.
Retaking Palmyra and its ancient architectural ruins would be a huge symbolic victory for Syrian forces but the area is also strategic city on the way toward the Iraqi border.
The IS has already demolished the famed Temple of Bel and at least two other antique structures as part of its campaign to destroy pre-Islamic monuments.