- Summary- 3 jets hit rebel group's anniversary event - reports- Military fighting resistance on multiple fronts- U.N., western missions condemn attack- Rebels, shadow govt accuse junta of war crimesOct 24 (Reuters) - An air strike killed at least 50 people at a concert in Myanmar held by an ethnic minority group in conflict with the ruling military, opposition groups and media said on Monday, an attack condemned by the United Nations and western embassies.A spokesperson for the junta could not immediately be reached for comment and state television made no mention of the incident in its nightly news bulletin on Monday.Register now for FREE unlimited access to Reuters.comIt took place in the A Nang Pa region of Hpakant township and killed at least 50 people, BBC Burmese said, while news site Irrawaddy put the death toll at about 100.KIA spokesperson Naw Bu said the attack targeted celebrations of the 62nd anniversary of the founding of the Kachin army's political wing, the Kachin Independence Organisation (KIO).Since the coup, open conflict has resumed between the Myanmar army and bitter rival the KIA, which has been fighting on and off for six decades for greater autonomy for the Kachin people."