An explosion in a public market in the southern Philippines on Sunday killed at least 11 people and injured nearly 30 others, police said.

The mid-afternoon blast destroyed at least two stalls in the market's meat section in General Santos city, police said.

Eight other people later died in hospitals, a police official said.

"The market was packed with people because there were Christmas flea market stalls there, and the explosion was powerful,'' he said.

No group has claimed responsibility for the blast yet and it was not yet clear if terrorist groups were involved, police said.