By Syed Shoaib Hasan
BBC News, Islamabad
Police in the south-western Pakistani province of Balochistan say they have detained 12 suspects over a series of deadly blasts on 26 and 27 May.
Locals say more attacks can be expected
The attacks in the provincial capital, Quetta, left two people dead.
Afterwards a gun battle between militants and security forces claimed another four lives on 28 May.
The attacks come as nationalist rebels, fighting for greater autonomy, have increased their activities in the province after a year-long lull.
"We have arrested a dozen suspects," local police chief Rahmatullah Niazi told a local TV channel.
However, militant activity continued across the province.
Hours after the arrests, a bomb blew up outside a government building in Kharan district approximately 200km (125 miles) south of Quetta.
A day earlier, a gun battle between tribal militants and intelligence agents backed by pro-government tribesman left four people dead and at least seven injured.
Both the militants and the pro-government tribesmen belong to the Bugti tribe.
The fight took place after intelligence officials, backed by the tribesmen, moved to arrest a wanted militant in a busy market in the eastern Jaffarabad district.
At least one of the dead and two of the injured were bystanders.
The violence - which first began in 2000 - reflects the recent rise in the level of armed activity after a 10-month ceasefire.
That began after the security forces killed one of the rebel leaders, Nawab Akbar Bugti, in a battle in August 2006.
Dozens of militants and security personnel were also killed in the fighting, which stretched over two days.
The remaining leaders of the resistance are said to have since gone underground or abroad.
Analysts are divided over whether the recent incidents suggest a revival of militant activity or are just the dying breaths of Baloch nationalism.
But local correspondents are adamant that the militants are staging a comeback, and will increase their attacks in the coming months.