An Iraqi Shia militia commander has said it had fired six mortar bombs into Saudi Arabia's desert as a "warning message" to the kingdom to stop "interfering" in Iraqi affairs.
"The goal was to send a warning message to Saudis to tellthem that their border stations and patrol are within our range of fire," Wathiq al-Batat, commander of al-Mukhtar Army militia, told Reuters by telephone.
Mr Batat said the militia had also been angered by Saudis and Kuwaitis who he said had insulted the daughter of the Prophet Mohammad.
The mortar rounds hit desert on the far northwestern fringes of the kingdom's oil-producing region and several hundred kilometres from the major fields operated by the world's largest oil exporter and biggest Arab economy.
Meanwhile, a car bomb exploded in a busy market in northeastern Iraq, killing at least 25 people and wounding more than 30, the town's mayor and medical sources said.
Iraq is suffering its worst wave of violence in at leastfive years, with insurgents targeting mainly Shia Muslim civilians in attacks on public places such as shopping areas and cafes.
Hundreds of Iraqis have been killed each month in 2013 and the frequency and severity of bomb attacks has raised fears that Iraq could descend once more into the kind of sectarian bloodshed of 2006-2007, when tens of thousands died.
Insurgents, some linked to al-Qaeda, have also benefited from the civil war in neighbouring Syria.