Three helicopters and two ships on Sunday joined the search operations for 50 fishermen missing off Andhra Pradesh coast for last five days, officials said.Three choppers including two belonging to Oil and Natural Gas Commission (ONGC) and two ships of the Coast Guard were searching for the missing fishermen.As many as 121 fishermen had left in boats for deep sea from Kakinada coast in East Godavari district on June 16 but 50 of them have not yet returned.With heavy rains lashing the region, the families of the fishermen grew anxious. They appealed to the state government to take immediate steps to safely bring them back.A report in The Hindu, quotes sources and adds that the engines of two boats could have failed leaving them drifting in the sea. It also added that each boat normally carried about six fishermen.Chief Minister N. Chandrababu Naidu reviewed the situation with officials. He said that the government is making all efforts to bring the fishermen back and asked their families not to panic. With IANS