Many of those displaced civilians "faced the risk of unlawful killings, enforced disappearances, torture, arbitrary arrests, displacement and burning and destruction of their homes," the watchdog said.

"In a 40-year-old conflict, the cumulative numbers of victims of human rights violations is really increasing, and it has reached very, very alarming levels."

Aurora Parong,
Amnesty International

Releasing the report Aurora Parong, Amnesty's director for the Philippines, said the group had documented incidents where men who returned to their ruined villages to salvage crops after attacks by the militants were often accosted by the military and accused of being combatants.

"There has been an alarming level (of these incidents) since fresh conflict began in August last year," Parong told reporters.

Many of the abuses had gone under-reported in the Philippine media, she added.

Parong said Amnesty was particularly concerned over reports that the military has labelled the displaced communities as potential MILF bases, where rebels could stage attacks on military targets.

"That is an alarming situation that would make the IDPs (internally displaced persons) targets of security forces," she said.

"In a 40-year-old conflict, the cumulative numbers of victims of human rights violations is really increasing, and it has reached very, very alarming levels."

The 12,000-strong MILF has been waging a rebellion for an independent Islamic state on Mindanao since 1978.