QUETTA, Nov 10: The police on Monday arrested 150 Afghan nationals staying in Quetta without proper legal documents on suspicion of their being involved in terrorist acts, Balochistan’s police chief said.

“We have rounded up over 150 illegal Afghan immigrants. They are being investigated for their alleged (involvement in) criminal and terrorist activities,” chief of the Balochistan police Dr Shoaib Suddle said on Monday evening.

The provincial metropolis has been battered by rocket attacks and bomb blasts for the past few weeks in which at least five persons were injured.

Sources said that all of the arrested Afghan nationals were living in the hotels or houses of their acquaintances in Quetta.

The provincial police chief said that these arrests were part of a campaign to curb incidents of terrorism in the province.

Dr Suddle said that all of them had been detained for violating immigration laws, adding that they would also be grilled to determine the level of their involvement in terrorism.

Those, he said, not found to be involved in terrorism would be deported to Afghanistan.

It was learnt that security had been tightened along the border between Pakistan and Afghanistan with scores of Afghans being arrested for trying to enter into Pakistani territory without proper documents.