WORLD IN BRIEF : YEMEN : Fierce Fighting Pits North Against South

Hundreds of Yemeni soldiers were killed or wounded in fierce clashes between northern and southern troops at a joint military camp near the capital, southern authorities and Western diplomats said. But northern security officials put the casualty toll much lower--at dozens killed and hundreds wounded. Fighting has flared over the last two days at a camp about 40 miles north of Sana, the capital. The battles in the impoverished Red Sea nation threaten to unravel a nearly four-year union of the conservative north and the formerly Marxist south. Merging of the two countries’ armies--one of the last steps of the unification process--has not been completed.