Al Qaeda militants in Yemen killed two alleged Saudi spies on Wednesday, residents said, accusing them of planting tracking devices which enabled the assassination of the group's leader in a suspected US drone strike last week.
Residents said al Qaeda charged the men with planting chips which pinpointed the location of several al Qaeda commanders slain in recent months, including its boss Nasser al-Wuhayshi, whose death along with two other militants was announced on Tuesday.
Images posted on social media by al Qaeda supporters showed armed militants on a beach carrying banners surrounding two blindfolded men kneeling on the sand.
"They executed two Saudis, named al-Mutairi and al-Khaledi. They put the two men on the corniche in the city of Mukalla ... they opened fire at them in front of a big group of residents," one resident, who was present on the beach, told Reuters via telephone. He asked to stay anonymous for his own safety.
The men's corpses were later pictured tied to wooden planks and hung from a bridge beneath a banner saying, "The House of Saud directs American planes to bomb the holy warriors." Later on Wednesday, residents reported that a suspected US drone bombed a Mukalla hotel used by al Qaeda militants, killing six people.
Wuhayshi, former aide to Osama bin Laden, also served as deputy leader of al Qaeda's global organisation, and his assassination deprives al Qaeda of a charismatic leader who directed a series of ambitious attacks.
AQAP has plotted foiled bomb plots against international airliners and claimed responsibility for the deadly shooting at the French satirical newspaper Charlie Hebdo, calling it punishment for insulting the Prophet Mohammed.
It has also orchestrated attacks inside Yemen in recent years, targeting government ministries, military camps and soldiers, which killed hundreds of people.
Despite evacuating its embassy and intelligence officials from Yemen this year, the United States has killed five other senior figures in AQAP in 2015, but the organisation may be empowered by the civil war raging in the country.
Analysts and Yemeni government officials say the strikes often rely on local informants.
Saudi Arabia has used a network of tribal and family connections to infiltrate AQAP in Yemen, and a tip-off from Riyadh helped foil a planned suicide bomb attack on a plane over Detroit in 2009.
The Yemeni off-shoot of al Qaeda has operated openly in Mukalla, the capital of Yemen's southeastern province of Hadramout, since army forces withdrew in April, taking advantage of months of political chaos and violence.