People across southern Asia have paused to remember the powerful Indian Ocean earthquake and tsunami that occurred one month ago Wednesday.

Thousands of Sri Lankans observed a minute of silence, and the Tamil Tiger rebels declared a day of mourning.

In Indonesia's hard-hit Banda Aceh province, teachers and students opened their first day of classes since the tragedy with prayers for missing friends. 

A senior USAID official tells VOA that aid workers continue to focus on survivors' emergency needs, but says there are signs that relief efforts have begun moving into a rehabilitation phase.

The Oxfam international charity says the response to the disaster has been so overwhelming that some aid groups are conducting relief work without the necessary experience or skills.

Some information for this story provided by AP.