Fifteen people on their way to a wedding in Yemen were killed in a suspected US air strike after their party was mistaken for an al Qaeda convoy, local security officials said on Thursday.
Tribal and local media sources said that the attack was carried out by a drone.
"An air strike missed its target and hit a wedding car convoy, 10 people were killed immediately and another five who were injured died after being admitted to the hospital," a security official said.
Five more people were injured, the officials said.
The United States has stepped up drone strikes as part of a campaign against al Qaeda in the Arabian Peninsula (AQAP), regarded by Washington as the most active wing of the militant network.
Yemen, AQAP's main stronghold, is among a handful of countries where the United States acknowledges using drones, although it does not comment on the practice.
Human Rights Watch said in a detailed report in August that US missile strikes, including armed drone attacks, have killed dozens of civilians in Yemen.
Stabilising the country, which is also struggling with southern separatists and northern rebels, is an international priority due to fears of disorder in a state that flanks top oil producer Saudi Arabia and major shipping lanes.
On Monday, missiles fired from a US drone killed at least three people travelling in a car in eastern Yemen.