NEW DELHI, Jan. 8 -- Two Italian marines, accused of killing two Indian fishermen off the southern state of Kerala's coast in 2012, Wednesday failed to appear before a special court in the national capital.

The court had in December last year summoned the two Italian marines -- Massimiliano Latorre and Salvatore Girone -- and set Jan. 8 as their appearance date in the wake of a plea by the country's anti-terror National Investigation Agency (NIA) which sought custody of the accused in the case.

However, the counsel for the two marines -- currently out on bail and working at the Italian embassy in the Indian capital -- told judge Dharmesh Sharma that there were certain "legal issues" which needed to be addressed before the special court could decide on the aspect of the custody of the accused.

He also sought exemption from personal appearance by the two marines on the ground that the NIA was yet to file a charge sheet in the case, to which the public prosecutor protested.

However, the court granted the two marines personal exemption from appearance for the day, saying, "Without going into the merits of the applications (of the marines), accused are exempted from personal appearance for today."

But, the judge asked the two marines to respond to the NIA's plea within 15 days and set Jan. 30 as the next date of hearing.

The case dates back to February 2012 when the two marines on board an Italian merchant vessel fired at a group of Indian fishermen allegedly mistaking them as pirates, in which two fishermen were killed off the coast of Kerala.

The marines were subsequently arrested and got bail after being in custody for several months in Kerala, before the Supreme Court stepped in and allowed the NIA to probe the case against them in the special court in the national capital.

The incident had sparked a diplomatic row between India and Italy. While Italy says the alleged killing took place in international waters and seeks the two accused to be tried in a global court, India insists that the marines had fired at the fishermen on this country's territorial waters.