Iran says it has protested an alleged incident in which British troops surrounded an Iranian consulate in Iraq and fired shots into the air.
Iran's state news agency (IRNA) reported Sunday that a letter of complaint had been sent to the British Embassy in Tehran.
The British military has denied the accusations, saying its troops briefly exchanged fire with gunmen Thursday while on a routine patrol in the city of Basra. But officials said troops did not surround the consulate building.
The spat comes amid a standoff over Iran's detention of 15 British sailors and marines.
On Saturday, President Bush characterized Iran's detention of the 15 as inexcusable behavior, and called for their immediate release.
The president said he supports the efforts of Britain's government to free the hostages.
In Tehran Saturday, Iranian President Mahmoud Ahmadinejad repeated his government's contention that the Britons illegally entered Iranian waters. He scolded Britain for refusing to apologize or express regret for the situation.
London's "Sunday Telegraph" published a story today saying the British government may send a senior naval officer to Tehran to deliver a public assurance that the Royal Navy will not knowingly enter Iranian waters without permission.
Some information for this report was provided by AP and Reuters.