Artists perform during a concert in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

Spectators react during a concert in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

Artists perform during a concert in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

Spectators react during a concert in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

People attend a celebration in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

Spectators watch a concert in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

People attend a celebration in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

Photo taken on Aug. 30, 2019 shows historic sites in the ancient city of Palmyra, Syria. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

People attend a celebration in the ancient city of Palmyra, Syria, on Aug. 30, 2019. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)

Photo taken on Aug. 30, 2019 shows a historic site in the ancient city of Palmyra, Syria. The Syrian government held a concert hailing the Syrian army's victories in the ancient city of Palmyra that was stormed by the Islamic State (IS) twice during the long-lasting Syrian war. (Photo: Ammar Safarjalani/Xinhua)