Almost 700 scientists have resigned from the Defence Research & Development Organization (DRDO) - India's premier military research organization - over the last six years, Defence Minister AK Antony said.

In a written reply to a question in the Rajya Sabha on departure of scientists from the DRDO, Mr. Antony admitted on Wednesday that a total of 637 scientists had quit the military research organization between 2007 and 2011, while another 50 scientists had quit till October 31 this year.

Antony also admitted that better opportunities and incentives available in other organizations was apparently the biggest cause of the scientists' departure.

In the reply, the minister said, "Scientists who have resigned indicated their personal/domestic grounds as the reasons. However, it is assumed that increased opportunities/incentives available in other organizations/industries are the main reason."

The minister also disclosed that it was the younger scientists and not the senior ones who quit the DRDO to pursue better opportunities elsewhere.

Observers say that what is more worrying is that the DRDO's has remained unsuccessful in attracting scientists and engineers from top-notch institutes like IITs in sufficient numbers.

Responsible for India's all key defence & strategic projects, ranging from designing and development of missiles to fighter planes, the DRDO currently has more than 7,500 scientists and engineers on its rolls.