The arrests were made last night from Radbeen area of Turbat in Baluchistan province, according to the security official.
"Total 18 people were arrested, which 16 are foreigners and two Pakistanis. Among the foreign nationals, 15 were Nigerians and one was from Yemen," he said.
He also said that the told that they were illegally traveling to Europe.
The arrests came after bodies of 20 people were found in Turbat last week. They were also going to Europe illegally but were killed by militants.
The Pakistan's Supreme Court has also taken suo motu notice of Turbat killings.