PALMYRA -- ANOTHER LANDMARK STRUCTURE DESTROYED

Another landmark structure in Syria’s ancient city of Palmyra has been deliberately destroyed by Islamic State militants, according to local antigovernment activists and Syrian officials. The building involved this time was a set of triumphal arches, erected in the second century.

Since seizing Palmyra from government forces in May, Islamic State fighters have destroyed some of the most beautiful and historically significant monuments in the sprawling oasis city in Syria’s central desert, one of the world’s most renowned archaeological sites. The latest to fall was the triple arch built by the Romans to celebrate a victory over the Persians, which bore ancient inscriptions and stood at the entrance to a grand colonnade.

Militants of the Islamic State, also known as ISIS or ISIL, had already blown up the temples of Baalshamin and of Baal, in keeping with their stated belief that such structures are idolatrous. But the arch was not a religious structure.

As it expanded across Iraq and Syria, the Islamic State destroyed many archaeological sites, looting them for profit and damaging some for propaganda. Residents of Palmyra have also suffered under intensified bombardment by government warplanes over the past month, some of which did their own damage to the archaeological site, Mr. Homsi and others said.