Eleven members of Iran's elite Revolutionary Guards force have been arrested in Pakistan after illegally entering the country, police there say.
Pakistan has detained 11 Iranian "security officers" on its border after giving chase to some smugglers.
They were detained in Mashkel near the Pakistan-Iran border, they added.
Earlier, local officials had said they were members of the elite Revolutionary Guards force, but later reports made no reference to this.
It comes eight days after a suicide bomb killed 42 people, among them six Revolutionary Guard commanders, in Iran's Sistan-Baluchistan province.
The Iranians were detained near Mashkel district, after shooting out the tyres of the smuggler's car, reports say.
Iranian state TV says some of the men were "border guards hunting smugglers who had accidently entered Pakistan."
A Pakistani security official said the Iranians were arrested about four miles (seven km) from the border with Iran.
Pakistan officials said the detainees had been travelling in two cars without travel documents.
The Iranian official state news agency interviewed the commander of Sistan-Baluichstan's border guards, who says eight of his personnel were detained.
General Gholam-Nabi Kuhkan said: "Pakistani local security forces arrived [at the scene] and arrested the [Iranian] police members as well as three smugglers.
"Pakistan's police have contacted [Iran]... saying they could not distinguish the police from the smugglers... and had to arrest them all.
"Final arrangements are being made to release the police personnel," he added.
The arrests come just over a week since a suicide bomb killed 42 people, among them six Revolutionary Guard commanders, in Iran's Sistan-Baluchistan province.
Iran said a Sunni militant group had launched the attack from Pakistan. Islamabad denied any involvement.
Iran said a Sunni militant group had launched the attack from Pakistan. Islamabad denied any involvement.
Pakistani officials said the 11 Revolutionary Guards arrested on Monday were being questioned. Two vehicles were also reportedly seized.
Last week, Iran's President Mahmoud Ahmadinejad called on Pakistan to arrest the attackers, believed to belong to a group called Jundallah, or Soldiers of God.
Pakistan condemned the bombing and said it would co-operate in the search for those responsible.
But Pakistani foreign ministry spokesman Abdul Basit dismissed Iranian claims that Jundallah's leader was in Pakistan.
Tehran had previously accused the US of contributing to the attack. The US dismissed the accusation.
'Fighting oppression'
According to Iranian state media, one or more suicide bombers targeted the group of Revolutionary Guards leaders, who had arranged to meet tribal leaders in Iran's Pishin district close to the Pakistani border.
The deputy commander of the Guards' ground force and the Guards' chief provincial commander were among six officers killed. Dozens of people were injured.
Jundallah has previously been accused by Iran of terrorist activities in the province.
The province borders both Pakistan and Afghanistan, and has long been affected by smuggling, drug trafficking, banditry and kidnapping.
Jundallah, also known as the Popular Resistance Movement of Iran, says it is fighting against the political and religious oppression of the country's minority Sunni Muslims.
Local media cited officials as saying Jundallah had accepted responsibility for Sunday's bombing, though there was no direct claim from the group.
