Wahyudi's act of heroism would be his last. The 47-year-old security guard rushed out of the Bank Mandiri Tebet branch in South Jakarta on Thursday morning and vainly tried to help a customer, Ferdinan, who had been shot in the leg by one of four robbers.

When he saw Wahyudi, one of the gang again fired his gun. A bullet hit him in the head, while another injured a bystander and a woman withdrawing money at a nearby ATM.

After grabbing the money -- Rp 75 million in total -- the four robbers fled on motorbikes, waving their weapons at shocked passersby.

Wahyudi along with the other injured were quickly taken to a nearby hospital but the security guard -- a father of four -- died a few hours later.

Jakarta Police general crimes unit chief Sr. Comr. Moh. Jaelani said police were looking for four men believed to be members of an established bank-robbing syndicate in the capital.

They had not yet identified the gang members and would continue to gather information from witnesses in the area.

"The robbers killed a bank security guard in Tebet. We are now chasing after the four men," Jaelani told The Jakarta Post.

Witnesses told police that Ferdinan, who had intended to transfer money from his BCA branch to a Mandiri one, had been followed by the robbers on motorbikes since he took the money from the branch in Gudang Peluru, not far away from Mandiri's Tebet branch.

One motorcycle entered the Mandiri compound at about 10:30 a.m., with the other waiting by the road.

When Ferdinan got out of his car, one of the robbers gave a warning shot, and asked him to hand over his bag. Ferdinan refused and the robber shot him in the leg.

Jaelani said witnesses described the culprits as being in their early 20s. The killer carried a white revolver, and wore a white T-shirt, he said.

Police say more than a dozen armed robberies have occurred in December.

Early this month, Suhartono, 58, a businessman was robbed by five people on his way home from a bank in South Jakarta. They got away with Rp 35 million.

Several days later, a group of armed robbers injured another businessman identified as Komarudin on his way home to Karawaci, Tangerang, and fled with Rp 300 million