MANILA - (UPDATE) At least 22 were wounded in several blasts which rocked Cotabato City and 2 other towns in the provinces of Cotabato and Maguindanaoprovince Sunday night.
A grenade exploded at 6 p.m. on the corner of Sinsuat and Quezon Avenues near the Immaculate Concepcion Cathedral in Cotabato City.
At least 12 were wounded in the grenade blast, the police said. Among those who hurt in the blasts were 8 soldiers conducting patrols in the area.
An improvised explosive device detonated nearby a few minutes later. A passerby was slightly wounded in the second explosion.
Meanwhile, 6 others were wounded in 2 blasts in the town of Libungan, Cotabato province the police said.
Two others were wounded in another blast in the town of Upi, Maguindanao. Local police said another bomb was thrown into a police station but did not explode.
Authorities have appealed to the public to stay alert and report anything suspicious.
The military and police are still investigating the incidents.
No groups have yet claimed responsibility for the attacks, which happened as the government planned this year to lift its military rule in the island over the improving security situation.
"We do not discount the possibility that Bangsamoro Islamic Freedom Fighters (BIFF) and Daesh-inspired groups are behind this," said Major Arvin Encinas, spokesperson of the military's Western Mindanao Command, referring to the Islamic State-linked militants.
The Philippines is plagued by violent insurgencies, including a Muslim-led separatist uprising in Mindanao that has killed some 100,000 people.
Though a landmark peace deal with the largest of the rebel groups, the Moro Islamic Liberation Front, was sealed in 2019, the most brutal extremist factions were not included.
Those groups include the Islamic State-aligned BIFF and Abu Sayyaf, a kidnap-for-ransom gang that has been behind some of the nation's deadliest attacks.
Two people were killed and 35 wounded in Cotabato in December last year after a bomb went off outside a shopping mall, which was also blamed on Islamic State-linked militants.
A worrying escalation of militancy was recorded in June when a Filipino jihadist -- who military named as the first local suicide bomber -- blew himself up in an attack on a military base.
Islamic State has stepped up its strategy of absorbing existing insurgent groups around the world as its "caliphate" crumbled in the Middle East.
In May 2017, hundreds of pro-IS gunmen seized the Muslim city of Marawi, sparking a five-month battle that left more than 1,000 people dead.
- With reports from Ariane Apatan, ABS-CBN News and Agence France-Presse