Mexican police have found a mass grave near the Pacific resort of Acapulco, holding what they believe to be victims of the country's drug war.
So far 18 bodies have been recovered but officers were due to conduct further searches of the site.
Police have so far not confirmed the identities of the dead, fuelling speculation they may be from a group of 20 men abducted over a month ago.
The region is the scene of a violent turf war between rival drug cartels.
Police officers and troops went to examine a site just outside Acapulco, following an anonymous telephone call alerting them to two dumped bodies.
There they discovered two murdered men with a message beside them, saying: "The people they killed are buried here."
Officers began digging and recovering bodies from the mass grave.
Authorities said they could not confirm that the victims in the grave were among 20 men from the neighbouring state of Michoacan who were kidnapped by gunmen on 30 September while visiting Acapulco.
In a grisly development, a video had earlier appeared on YouTube showing two men, with their hands apparently tied behind their backs, saying they killed what they called the "20 michoacanos".
They tell an unseen questioner they were ordered to kill them in a revenge attack against La Familia Michoacana, a violent drug cartel active on Mexico's Pacific coast.
The two men discovered lying by the mass grave were wearing the same clothes as the men in the video.
A police spokesman said DNA tests would be needed to confirm the identities of the victims found in the grave.
Mass killings and the discovery of mass graves have become more frequent in recent months, while the use of gruesome video messages has also become more common.
More than 28,000 people have died in drug-related violence in Mexico since December 2006 when President Felipe Caldeorn began deploying troops to take on the traffickers.