SEOUL, May 6 -- South Korean President Park Geun- hye on Tuesday made another official apology over the recent deadly ferry sinking tragedy, which claimed more than 200 lives.

The president told a celebration ceremony of Buddha's birthday in Seoul that as a president, culpable of keeping people's safety, she expressed her deep apology for the victims and their family members.

She pledged that the government will learn a lesson and carry out a thorough reform over regulations and social systems to prevent disasters.

The ceremony was held at the Jogye temple in Seoul, the major monastery of the country's largest Buddhist sect.

Park was the first incumbent South Korean president to attend the ceremony.

"I pray for the souls of the victims and wish Buddha's mercy to be with the bereaved families who lost their loved ones," said the president.

She quoted Buddha's principle that appreciates all living things to stress her commitment to carry out reforms, battling irregularities and corruption.

Park made an official apology last Tuesday during a cabinet meeting, saying she was "sorry to the people and heavy hearted that many precious lives were lost."

She also apologized for the government's failure to prevent the accident and for its insufficient initial response to the accident.

Many families of the victims, however, rejected the close-door apology, demanding for a public one.

The rescue efforts were hampered by high waves and rapid currents on Tuesday, the 21st day since the passenger ship Sewol capsized off the country's southwestern coast on April 16.

As of Tuesday, 263 people have been confirmed dead, with 39 still missing.

A 53-year-old male civilian diver died on Tuesday morning after falling unconscious during a mission, officials said.

South Korea's Coast Guard officials suspended all search operations following the accident.