Anguish gave way to anger as relatives of 154 Chinese passengers on the missing Malaysian Air jet, after learning there’s no hope their loved ones are alive, accused the carrier and Malaysian leaders of a cover-up.

Confusing information about Flight 370, which disappeared March 8, “misled and delayed the rescue, wasting tremendous manpower and resources as well as the most precious rescuing time,” one man read in a statement, surrounded by about 30 family members at 2 a.m. in Beijing’s Metropark Lido Hotel.

Hours earlier they were part of a larger group brought to the hotel ballroom to watch on television as Malaysian officials concluded the Boeing 777-200ER disappeared into the southern Indian Ocean, leaving no hope of survivors. Wails and screams punctuated that meeting, and at least two relatives were carried away on stretchers while police guarded the entrance.

“If the 154 passengers lost their precious lives, then Malaysia Airline, Malaysian government and Malaysian military are the executioner of our families,” the relatives said in the statement.

Frustration has mounted for passengers over the slow pace with which officials have released information on Malaysian Airline System Bhd.’s plane, now missing for 18 days. Analysis of satellite data rules out the possibility the plane may have flown north over land and that “its last position was in the middle of the Indian Ocean” west of Australia, Malaysia’s Prime Minister Najib Razak said yesterday.

Najib’s pronouncement may have been intended to counter criticism that Malaysian officials have been too reticent to share details of the search, said Richard Aboulafia, an aerospace analyst with Teal Group, a consultant based in Fairfax, Virginia.

“It’s not much closure, but it’s better than none at this point,” Aboulafia said in a telephone interview.

That’s proven illusive for Li Bo, 40, a Heilongjiang native whose cousin — an only child — was on the missing plane. He lashed out at photographers who clamored to take his picture outside the ballroom, cutting his arm in the melee.

“There is no evidence,” Li said after watching Najib’s televised statement in the Lido ballroom. “If you have evidence of something floating on the sea we can accept it. But now there is nothing.”

The conclusion that the plane was lost at sea, drawn from a new analysis by satellite operator Inmarsat Plc and British air safety regulators, isn’t credible, Li said in an interview. “You can’t make a judgment based on Malaysia’s data.”

Family members have turned to Weibo, a Chinese-language social media site similar to Twitter, to express their anguish and response to events that have mystified the world.

Chanting in unison at the Beijing hotel, they said they “protest and condemn” the inaction by Malaysian officials. “We will take all possible means to prosecute Malaysian Airlines, Malaysian government and Malaysian military unforgivable guilt and responsibility,” they said.