WASHINGTON: Yet another Indian doctoral student has been shot dead - the third in a month - on a US university campus, raising questions about the safety of the American university environment.

The bullet-riddled body of 29-year old Abhijit Mahato was found inside his Anderson Street apartment in North Carolina's Duke University on Friday, nearly a month to the day after two other Indian PhD students were killed execution-style at Louisiana State University.

Police are still investigating the cause and motive for Mahato's killing, even as the December 17 LSU murders are yet to be solved.

Mahato, originally from Kolkata and Tatanagar, India, was studying for an engineering doctorate degree focused on computational mechanics at Duke's Pratt School of Engineering, university officials said. He was in his second year.

Earlier, he had earned his mechanical engineering degree from Jadavpur University in 2001 and an M.Tech from the Indian Institute for Technology (IIT) in Kanpur in 2004.

Before coming to Duke, Mahato worked for two years for the GE Global Research Center in Bangalore, where he focused on finite element analysis, a computer-simulation technique used in engineering. The experience prepared him well for his graduate work, according to Mahato's adviser, engineering professor Tod Laursen.

"We were working together on an industry-funded research project and Abhijit's prior industry experience helped him develop close working relationships with our partner," Laursen said. "He understood their needs as a business and was a pleasure to work with."

Even as the incident sent shock waves among the huge Indian student community in the US – the biggest from any foreign country, Duke officials tried to reassure the students.

Some 80,000 students come to the US each year for studies and the total Indian student population in the US is said to be over 250,000 at any given time.

Duke is one of the biggest campuses in the US with one of the racially and ethnically diverse student population (from 117 countries) including a large contingent from India. The University's Pratt School of Engineering is particularly popular among Indian students.

On a newly constructed web page on the school site, Mahato described himself as the "the newest person to join DUKE Computational Mechanics Lab ((DCML)" and said he is "interested in nonlinear continuum mechanics problems and developing numerical methods for them...working on large deformation two body contact problems."

Larry Moneta, Duke's vice president for student affairs, said the university has begun reaching out to Mahato's friends and to his family in India, as well as to Indian and other international students on campus. It is offering counselling services and has begun considering appropriate ways of commemorating Mahato's life.

"This is a tragic circumstance, and we are doing everything possible to assist those who may be affected by it," Moneta said in a statement issued by the university.

In the engineering department, Laursen met with his lab team to talk about Mahato, whom he described as intellectually curious, kind and outgoing.

"He made friends very easily and always had a smile on his face," Laursen said. "Our research team was particularly close to Abhijit. He was very well read in both poetry and literature, and enjoyed conversation with others about what they were reading."

Mahato said on his webpage that his "upbringing was in Kolkata; the City of Joy, the city of intellectuals, and much much more."