BANGKOK (AP) — The United Nations’ office in Myanmar has expressed concern about escalating human rights abuses after reports that opponents of the ruling military may have executed 25 civilians and allegations that troops burned down a village. The struggle between the military regime that took power in February after ousting the elected government and those opposing the takeover has sharpened in recent months. Elements of what had initially been a nonviolent civil disobedience movement have evolved into a fledgling armed resistance force. The U.N. office called on all parties in Myanmar to respect human rights norms and standards.