NATO accused Syrian President Bashar al-Assad's forces of firing Scud missiles that landed near to the Turkish border, in explaining why it was sending anti-missile batteries and troops to the bloc's frontier.

The Syrian government, which finds itself under attack from rebels in the capital Damascus and by a diplomatic alliance of Arab and Western powers, denies firing such long-range, Soviet-built rockets and had no immediate comment on the latest charge.

Admiral James Stavridis, the American who is NATO's military commander, wrote in a blog on Friday: "Over the past few days, a handful of Scud missiles were launched inside Syria, directed by the regime against opposition targets. Several landed fairly close to the Turkish border, which is very worrisome."