OE_HOLDS_PUB.RELEASE_HOLDS in Trigger

I'm trying to release the hold through Trigger by using OE_HOLDS_PUB API but it encounters error as 'cannot SET SAVEPOINT in a trigger in Package OE_Holds_Pvt Procedure Insert_Hold_Release' but the same code is working fine when written in procedure. Below are the used code, Please help me to understand what I'm missing

BEGIN

v_hold_id_newc:=2821;

v_header_id_newc:=39045647;

v_order_tbl(1).header_id           := v_header_id_newc;

v_return_status                    := NULL;

v_msg_data                         := NULL;

v_msg_count                        := NULL;

--****Call API to release the hold*******

OE_HOLDS_PUB.RELEASE_HOLDS (