The helicopters carry out a 20-minute attack on rebel positions in Zamboanga City . The armed forces are trying to `` constrict '' the rebels ' positions , a spokesman says . Authorities estimate that more than 60 people have been killed during the crisis . - A Philippine military helicopter crashes into Mount Pinatubo volcano near the city of Cotabato in central Philippines.
The helicopters carry out a 20-minute attack on rebel positions in Zamboanga City . The armed forces are trying to `` constrict '' the rebels ' positions , a spokesman says . Authorities estimate that more than 60 people have been killed during the crisis . The unrest in and around the port city has displaced more than 60,000 people .