QUETTA, Pakistan (Reuters) -- Pakistani authorities have released 11 Iranian Revolutionary Guards detained a day earlier for trespassing into Pakistani territory, officials said.
The guards were arrested in the Mashkhel area on the border with Iran eight days after a suicide bomber killed 42 people, including six Revolutionary Guard commanders, in Iran's southeastern Sistan-Baluchistan Province.
A Sunni Muslim group, Jundallah (Soldiers of God), claimed responsibility for that blast and Iran said the group operated from Pakistan. On October 20, a senior Revolutionary Guards commander said his force should be given permission to confront terrorists inside Pakistan, state media reported.
Officials said the 11 Iranians troops arrested on October 26 had accidentally strayed into Pakistan territory. Iranian state television said they were arrested while pursuing suspected fuel smugglers.
"The guards were handed over to the Iranian authorities because it's found that they crossed into Pakistan mistakenly," said a spokesman for Pakistan's Frontier Corps paramilitary force.
Relations between Iran and Pakistan have generally been good, but tension has risen after Iran said last week's suicide bombing would affect relations.
Iran says the Jundallah group has bases in Pakistan and it has urged Pakistan to hand over its leader, Abdolmalek Rigi.
Pakistan has assured Iran that it would cooperate in tracking down and punishing those behind the attack, but has denied that Rigi was in Pakistan.
Iran also accuses the United States and Britain of backing Jundallah.