India, June 13 -- The opposition parties on Saturday stepped up pressure on the Centre over the deaths of three Indian seafarers in US military strikes on commercial vessels off the coast of Oman, with NCP (SP) MP Supriya Sule demanding a stronger response from the government and promising support for the affected families.

The remarks came a day after India summoned a top American diplomat in New Delhi for the second time this week and lodged a strong protest over the attacks, which have claimed the lives of three Indian crew members and raised concerns about the safety of Indian mariners operating in the Gulf of Oman amid the West Asia conflict.

Calling the deaths "deeply saddening", Sule said India must take a firm position in defenc...