"It is shocking that the UPA government has not squarely condemned the incident and the External Affairs Minister has merely termed it as 'unfortunate'," the party Politburo said in a statement here.
"This lukewarm attitude stems from the fact that India is engaged in military collaboration with the US and the same US Navy which fired on the Indian fishermen is constantly engaged in joint naval exercises with the Indian navy," it said.
It said the "premeditated" killing of an Indian fisherman and injuries to three others due to firing by a US naval ship in the Persian Gulf within UAE waters was "a highly condemnable and reprehensible act".
CPI(M) said the country expected the government to demand that "the US naval personnel who committed this act of murder be arrested and put on trial", adding that this was the stand in the case of the Italian naval personnel who shot and killed two Indian fishermen off the coast of Kerala.
