BEIJING — Three Chinese men died from suffocation when they tried to rob an ancient tomb in the central province of Henan, known for its many relic-filled graves, local authorities said.

Five villagers had entered a chamber of the tomb near their village of Chengjiao when three of them fainted from a lack of air, Yiyang county police said in a statement posted on Monday.

The other two men called for help but attempts to rescue the three failed, police said.

One more man fainted during the rescue but was resuscitated, while the fifth tomb raider fled, police said.

Both men were later detained on the charge of robbing ancient graves.

Police did not say what caused the lack of air in the tomb or if the men managed to steal anything.

Known as a cradle of Chinese civilization, Henan is famous for the relics buried under its villages.