One report said the bombs were packed with nails
Two people have died in twin explosions at shops in the city of Iligan in the southern Philippines.
At least 47 people were injured - two critically - in the blasts, which went off minutes apart in two shops packed with Christmas shoppers.
Police have blamed "terrorists" for the bombs, and Philippines President Gloria Macapagal Arroyo has vowed to bring the perpetrators to justice.
Iligan is on the island of Mindanao, which has an active Muslim insurgency.
There have been sporadic clashes between government troops and rebels fighting for self rule since August, when a court blocked a land deal aimed at ending years of fighting.
The bombs appeared to be home-made, and one report said they were packed with nails.
They were placed at baggage counters close to the entrance of both stores where customers check their bags before shopping, police said.
Roger Alforque was standing at a counter with his family when there was an explosion, he told Associated Press news agency.
It sounded like a powerful firecracker "but it caused a lot of damage", he said, knocking his wife unconscious and wounding him and his 10-year-old daughter.
CCTV footage had captured two suspected attackers depositing bags at the baggage counter, authorities said.
Investigators are at the scene.
A spokesman for President Arroyo - who is due to visit Iligan on Friday - condemned the bombings.
"The government will not stop hunting these terrorists until they are put behind bars," Anthony Golez said.
Police in the southern Philippines say they have been on high alert for attacks since the government-rebel peace process broke down.
Dozens of civilians as well as combatants have died in the renewed fighting.