Two people were wounded Sunday when a bomb exploded about 150 yards from a UN office in eastern Afghanistan. Gen. Mohammad Ayub, the provincial police chief of Khost province, said a man carrying the explosives intended to put them under a bridge but they detonated early. The attacker survived the blast but was in serious condition in the hospital. A woman passing by was wounded. Aleem Siddique, a spokesman for the UN mission in Afghanistan, said it was too early to conclude that the UN building in Khost city was deliberately targeted.