Superintendent Sangacala Dampac, city police chief, said probers have no solid clues yet on the identities of the grenade-throwers.
There are suspicions though that the bombing could be linked to the Nov. 26 elections in the Autonomous Region in Muslim Mindanao.
"It is a known fact that a certain camp is against the holding of the elections. But while this angle is now being investigated, we are also looking into other possible angles," Dampac said.
The Nur Misuari-led faction of the Moro National Liberation Front (MNLF) is opposing the elections, aware it would result in Misuari’s replacement as ARMM governor.
Since 1999, Misuari has been functioning as governor on hold-over basis.
Misuari’s subordinates, however, belied insinuations that MNLF forces loyal to the governor could be responsible for the blast.
Dampac said the grenade went off at the doorstep of the Comelec’s regional office along Sinsuat Avenue.
"It was just fortunate that no one was there at the spot where the grenade exploded," he said.
Investigators were verifying reports that the grenade-throwers fled toward an intersection connecting the ARMM compound and the Cotabato City airport.
Maj. Julieto Ando, spokesman of the Army’s 6th Infantry Division, said their commander, Brig. Gen. Roy Kyamko, has dispatched more than a dozen intelligence agents to help the city police investigate the incident.
City Mayor Datu Muslimin Sema is a member of the Council of 15, the MNLF’s new central leadership which the national government and the Organization of Islamic Conference now recognize as the front’s new governing set-up.
President Arroyo and the council have a common candidate – Farouk Hussin – for ARMM governor.
Hussin is one of 15 key MNLF officials, among them Sema, Sulu Gov. Yusoph Jikiri and Marawi City Mayor Solitario Omar, who unseated Misuari as chairman early this year due to loss of trust and confidence in his leadership.
Only Hussin and an influential Maguindanaoan leader, Ibrahim Paglas III, are aspiring for the region’s gubernatorial post.