An American free-lance photographer was captured by Afghan government soldiers while traveling with Muslim guerrillas, rebel sources and the U.S. Embassy in Islamabad, Pakistan, said. Tony O'Brien, 42, a photographer from Santa Fe, N.M., on assignment for Time-Life Inc., was captured Wednesday in Kabul, the rebel sources said. A spokesman for the U.S. Embassy in Islamabad confirmed that O'Brien is being held in Kabul but gave no other details. The Afghan government did not confirm the capture immediately. O'Brien, whose photographs have appeared in several major U.S. publications, had made several forays into Afghanistan with the guerrillas.