The U.S.-led anti-terror coalition struck two key bridges on Friday that Daesh militants were using in eastern Syria  to move between Syria and Iraq, a monitor group reported.

The warplanes targeted two strategic bridges in the eastern province of Deir al-Zour, which were located on two main roads the IS militants were using to move between Syria and Iraq, according to the Syrian Observatory for Human Rights.

The Britain-based watchdog group said large chunks of the bridges were destroyed.

One of the bridges connects the Syrian city of Bukamal in the countryside of Deir al-Zour with the town of Bagouz in Iraq, while the other connects Bukamal with the town of Swaiyeh.

Though partial destruction of the bridges will not fully deter Daesh  movement between both countries, it will make it difficult, according to the Observatory, which relies on a network of activists on ground.

The U.S.-led anti-terror coalition started striking Daesh  positions in Syria in September of last year.