Initial police reports said the first blast occurred at about 5:30 a.m. at the Nilsan store along General Arolas street, in front of the Jolo public market, killing five people and wounding 40 others.
The second blast occurred at 2 p.m. when a grenade exploded inside Cinema B, which was then screening "Lord of the Rings," on the fourth floor of the busy Mindpro Citimall here, wounding at least four people.
The shopping mall is located in front of an open-air food court that was hit by a bomb blast last October that left six people dead and 56 wounded.
National Security Adviser Roilo Golez raised the possibility that the grenade attacks may be the handiwork of "ultra-militant groups" against the joint RP-US "Balikatan" military exercises which are being held here and on nearby Basilan island.
"It’s highly possible that the explosions in Sulu and Zamboanga are cowardly attempts to scare the Mindanao public and erode the overwhelming public support for the Balikatan exercise," Golez said.
"Of course, this lame attempt will only strengthen the government’s will to fight terrorism," Golez added.
Witnesses reported panic-stricken people fleeing the Zamboanga City cinema, some carrying bloodied victims and others sustaining slight injuries in the ensuing stampede.
"We heard an explosion inside and people were rushing outside yelling," theater security guard Jovi Pestano said.
Police reported no fatalities in the Zamboanga blast but identified the wounded as Catherine Gonzales, 27; Claribel Sy, 19; Jamielyn Ragayan, 15; and Charlie Marasigan, 14.
Marasigan sustained shrapnel wounds in his groin while the females were hit in their legs.
Chief Inspector Jose Bayani Gucela, intelligence chief of the Zamboanga City police, said they already have identified a number of suspects from the testimony of some witnesses.
Witnesses said the grenade, identified to be Belgian-made, was hurled by the perpetrators from the cinema’s balcony section, said Gucela, who added police are not discounting the possibility that Abu Sayyaf extremists could be responsible for the blast.
The blast in Jolo was may also have been the handiwork of the Abu Sayyaf, said Col. Romeo Tolentino, commander of the 104th Army Brigade based in the capital town.
Police said at least five people were killed in the Jolo blast but they could only identify 14-year-old Jose Guillermo as among the fatalities.
Tolentino said the Abu Sayyaf earlier sent letters to different Jolo schools threatening to abduct teachers and students if the military operations against them were not stopped.
The military said the grenade used was also an old model known to be favored by the group.
The military launched in Patikul town last week military operations against two Abu Sayyaf factions allied with followers of jailed rebel leader Nur Misuari which have so far resulted in the death of 27 Abu Sayyaf bandits and six government troopers.
However, Tolentino said the military and police have enforced stricter security measures in the town to normalize the situation.
While the authorities suspect the Abu Sayyaf are responsible for the explosion, he said they are not discounting the possibility that a local criminal syndicate may also be responsible.
"We imposed stricter measures against any group bringing firearms inside the market place and perhaps this irked a criminal syndicate that operates in the area," Tolentino said.
"But we could not discount the possibility this could be a diversionary tactic of the Abu Sayyaf to ease the military operations in Patikul," Tolentino added.
The area of the blast was also the site where Misuari loyalists ambushed a military jeep, killing three soldiers, last month.
Meanwhile, a bomb blast also rocked a laboratory in the state-owned University of Southern Mindanao on Friday while authorities found another bomb at the ground floor of the same building. No one was reported injured.
A bomb scare also hit the regional office of the Civil Service Commission and the Autonomous Region in Muslim Mindanao after an anonymous caller warned employees that bombs were planted in both offices. — With reports Jaime Laude, Marichu Villanueva