The International Committee of the Red Cross is making another attempt Wednesday to rescue wounded and ill civilians in Sri Lanka's only remaining combat zone. The ICRC's aid ship turned around earlier Tuesday due to heavy fighting but has returned for a second day in another attempt to unload desperately needed food and conduct an evacuation.

Sri Lanka's military says confrontations with the Tamil Tigers rebels are continuing on the northeastern coast and off shore.

The intense fighting is blocking the only humanitarian link to the 2.5 square kilometer combat zone where tens of thousands of Tamil civilians are trapped.

ICRC spokesperson Sarasi Wijeratna in Colombo tells VOA News small fishing boats are the only way to offload the 25 metric tons of food and bring the wounded and sick on board to its chartered ship (the Green Ocean).  

"The ferry is, at present, anchored off the Mullaittivu coast because the ground situation is not conducive for the food to be offloaded and for the patients to be put onboard the ferry so that they can be brought over to government-controlled areas for medical treatment," Wijeratna said.  

The last successful Red Cross evacuation was on Saturday when more than 500 sick and wounded civilians, and their relatives, were taken on board the vessel.

More shelling is reported to have hit a medical facility in the combat zone Wednesday. The rebel Liberation Tigers of Tamil Eelam and medical workers say there have been dozens of new fatalities.

The ICRC's Wijeratna says one of its aid workers is among the latest victims.  

"Mr. Majuran Sivakurunathan was killed when he was hit by a shell this afternoon," Wijeratna said.  "His mother was also killed at the same time as he was. She was also hit by a shell."

Diplomats and humanitarian officials, in recent days, have called on Sri Lanka's government to abide by its pledge it made last month not to fire artillery into the area where the civilians are trapped.  

The government has repeatedly insisted that it is not using such weapons and calls such reports propaganda generated by an enemy, desperate for international support, on the verge of defeat.

The military calls its final offensive to wipe out the LTTE "the world's largest hostage rescue mission," saying the civilians are human shields of the rebels.

In a joint statement, U.S. Secretary of State Hillary Clinton and her British counterpart, David Miliband, called on both the Sri Lankan military and the LTTE to cooperate with the ICRC.

A number of Western nations are calling for an immediate end to the hostilities to allow for the safe evacuation of the trapped civilians.