Mr Parrikar said the government had deployed 30 ships and submarines for the purpose.
There are 4-5 "small" leads with regard to the AN-32 aircraft of the IAF which went missing four days back with 29 people on board, the government told the Rajya Sabha as it faced questions over the issue.
During the Question Hour, Defence Minister Manohar Parrikar was asked about the status of the plane which disappeared during a flight from Tambaram airbase in Tamil Nadu to Port Blair on Friday last.
"There are 4-5 small leads and attempts are being made to verify them," he said, adding, however, that there has been no confirmed finding yet.
Asserting that the government had spared no efforts in locating the plane, Parrikar said the government had used satellite imagery and deployed 30 ships and submarines for the purpose.
Responding to questions about quality of AN-32, he said it is one of the safest aircraft and there have been reports of only two accidents in the last ten years. There have been some minor snags at times, he said.
Parrikar was also asked if the government was in talks with the US for conducting joint naval patrols in the South China sea over which China has laid a claim.
He replied that there have been no such talks.
The government takes all measures to ensure the country's maritime security, he said, adding these measures do not include joint patrolling with foreign navies including the US.
Asked about the implications of the China's refusal to accept international court's decision on the South China sea, Parrikar, without naming China, said any country should respect International Courts, whichever decision they have given. He added that "freedom of navigation cannot be compromised."