AMMAN - A missile struck the command center of the main Syrian rebel force near Damascus on Wednesday, wounding its leader, activists said, and a soccer player was killed when a mortar bomb hit a stadium in the center of the capital.The missile attack on Liwa al-Islam Brigade, which is spearheading a three-week-old offensive that has given the rebels a foothold inside Damascus, deals a blow to efforts to undermine President Bashar Assad in his seat of power.Activists said the early morning strike took place near the northern Damascus suburb of Douma. The rocket, possibly a Scud-type ballistic missile, devastated the area and killed or wounded other fighters, they said.Activists and Syrian state media later reported a mortar bomb had struck the Tishreen stadium in central Damascus, killing a player from the Homs-based soccer team Al-Wathba.