ISLAMABAD - Police in the Pakistani port city of Karachi said that six suspected militants were killed early Thursday and foiled a big terror plan on the eve of religious processions by the Shiite Muslims.

Those killed during a raid belonged to the outlawed sectarian "Lashkar-e-Jhangvi" group, which has links with the Pakistani Taliban and routinely claims responsibility for attacks on Shiites.

The suspects started firing on the raiding police party at Karachi's Mauripur area, injuring three police officers, Senior Superintendent of Police (SSP) Chaudhry Aslam told reporters.

He said the police launched a search operation following a tip- off that the suspects had been hiding in a compound and planned attacks in the city. "As the police party arrived at the scene the armed militants opened fire," he said.

The police officers returned fire and killed six militants and recovered arms including suicide vests. Three police officers were also injured, the Crime Investigation Department (CID) of police said.

The militants include Gul Hasan who was involved in over 50 cases of sectarian killings in Karachi, a police officer said.

He said the suspected militants were believed to be involved in the attacks on a high court judge and a Shiite worship place.

Police officer Aslam said the militants were planning to target a main mosque of the Shiite Muslims in Karachi prior to the religious gatherings on Thursday and Friday.

Shiite Muslims are set to hold processions on the ninth day of the holy Muslim month of Muharram to mourn the seventh century martyrdom of Imam Hussain (RA), the grandson of Prophet Mohammad ( PBUH), along with his family members in the desert of Karbala.

Meanwhile three low-intensity blasts in Karachi injured nearly 10 people late Wednesday, police said. Two policemen, a paramilitary soldier and media persons were among the injured.