A boat carrying six scientists of the Waltair-Vishkhapatnam-based regional centre of  National Institute of Oceanography in Panaji was attacked off the Yermal coast in Karnataka's Udupi district. No one was injured in the incident.

The attackers, boarding two canoes, alighted into the NIO boat two days ago and took away geo-physical survey instruments after a brief scuffle with the scientists, a NIO spokesman said in Panaji on Wednesday.

The NIO officials, who are yet to ascertain whether the act was a planned piracy or a petty robbery, said that they were still studying the incident.  The boat was hired by the NIO and did not belong to the institute, the spokesman said.

"All the six scientists from Waltair regional centre were on a sponsored project to the West coast to conduct research on sea variations and tsunami alerts," the spokesman said.

NIO Director V P Shetye said that the institute was assessing the loss incurred for the instruments. "A case has been registered with the Udupi police," he said.

 The institute will release a formal bulletin later, listing names of the scientists on board during the incident, officials said.