In its annual report, Amnesty International raised particular concern about the situation in Nepal, which it says has slipped "deeper into crisis" over the past year.
King Gyanendra grabbed power earlier this year amid a violent 10-year rebellion by Maoist insurgents. The report says both government security forces and the rebels have committed abuses, including hundreds of killings and abductions.
Robert Godden, regional coordinator for Amnesty International in Asia, says both sides must be held responsible for their actions.
"There are extrajudicial killings and disappearances by the military, but even when these are highlighted, the government fails to act… We also need to see that the Maoist insurgents adhere [to] international humanitarian law," he said. "We see again unlawful killings, torture by the Maoists, the recruitment of children for conflict-related work - there have been promises in the past by the Maoist leadership, but we need to see action."
Amnesty says human rights abuses remain rife in other conflict areas in the region. The report says violence in the Tamil Tiger stronghold of northeastern Sri Lanka has worsened since a split within the rebel group last year. While a ceasefire between the rebels and the government continues to hold, political killings among Tamils rose over the past year.
Amnesty also raised concern over the flare-up of violence in southern Thailand, and the unpunished deaths of Muslim protesters in police custody. These, and the lack of justice for the deaths of some two-thousand people in a recent government anti-drug campaign, have created what Amnesty calls a "climate of impunity" among Thai security forces.
The London-based group also criticized Asian governments' handling of the war on terror, which, it says, has trampled on human rights. Amnesty says hundreds of suspected Taleban and al-Qaida militants have been jailed arbitrarily in Afghanistan without access to lawyers. It says China has used the war on terror to repress minority Muslim Uighurs in China's Northwest.
In addition, the report said the situation for women in Afghanistan has barely changed since the fall of the Taleban in 2001. Amnesty says women continue to face discrimination and "systematic and widespread" violence, including rape.
The report criticizes Burma's suppression of the democracy movement, and North Korea's repression and starvation of its citizens.
But the group welcomed attempts at democratization and increased human-rights protection by Brunei, Bhutan, and the Maldives, efforts toward police reform in Malaysia, and the release from prison of Malaysian opposition leader Anwar Ibrahim.