ZAMBOANGA, Philippines (AFP) - A dog handler in the southern Philippines narrowly avoided death after his dog alerted him to a bomb just before it exploded, police said Monday.

Officer Manuel Ynid was only injured when the bomb hidden in a cardboard box exploded in the strife-torn southern port city of Zamboanga late Sunday, said the city police spokesman Chief Inspector Ariel Huesca.

Ynid and his bomb-sniffing Belgian Malinois called Diego were part of a team that was investigating an earlier explosion at a massage parlour, Huesca said.

The first bomb had caused no casualties but as Ynid was approaching a cardboard box, the dog reacted, indicating it had detected a bomb.

Just as they moved away from the box, the bomb inside exploded, wounding Ynid although the dog was unharmed.

Security officials said the bomb was made from ammonium nitrate and was possibly set off with a mobile phone.

Ynid is in stable condition while Diego, a three-year veteran who found a bomb in a public square last month, was given a week to recover from the stress, police officials said.

Authorities are still trying to determine who might have been behind the bomb blast.

Zamboanga has been the scene of Muslim rebel activity in the past.

Last year, die-hard Muslim guerrillas occupied parts of the city, resulting in three weeks of urban battles that left more than 240 dead.

The military is also carrying out operations in the islands south of Zamboanga, against the Abu Sayyaf, an Al-Qaeda-linked extremist group blamed for the country's worst terror attacks including bombings and kidnappings.