WATCH: Several blasts hit Jakarta

Several blasts Thursday in central Jakarta were caused by a bomb, Indonesian police said. 

"This is a bomb," Anton Charliyan, national police spokesman told AFP. 

He warned people to stay away, saying police fear there could be more bombs.

At least 4 people have been killed in multiple blasts while gunfire has also been heard. 

Authorities have confirmed that at least 6 explosions took place but haven't been able to confirm who's behind the attacks.