Three?policemen and an auxiliary police officer were shot dead Tuesday while investigating a murder case in east China's Shandong Province, with?several others, including two civilians, wounded in ensuing gunfire.

Four officers were gunned down at around 11:20 a.m. Tuesday after knocking on the door of a home belonging to a murder suspect's brother in Tai'an City of Shandong.

After the initial shootings, the two gunmen hijacked a car and fled the scene, said a spokesman with the government information office of Tai'an City.

They later hijacked four other vehicles -- shooting two of their drivers while doing so -- before their car was hit by a police vehicle.

The gunmen continued to fire after police cornered them, wounding more police officers.

One gunman finally shot himself and died. The other was arrested by police.