|The remotely detonated bomb on a cycle in Quetta killed three police officers [EPA]
A series of attacks across Pakistan have left at least 38 people dead, according to government officials.
Pakistani troops killed at least 24 rebels after several security checkpoints were attacked in a northwestern tribal region on the Afghan border, military officials said.
Amjad Ali Khan, an administrator of Mohmand Agency, confirmed that 11 soldiers had been killed, and 12 others wounded, in that attack.
In a separate incident, three police officers were killed in Quetta, when a bomb exploded near their vehicle.
A statement from the Frontier Corps security force, a paramilitary division of the military, said that around 150 fighters staged simultaneous attacks using small and heavy weapons on five army checkposts in the Baizai area of the Mohmand tribal agency on the Afghan border on Friday.
The Taliban said only two of their fighters had died.
Khan said the Frontier Corps paramilitary troops had "repulsed" the rebel attacks in the Baizai area which began at 0200 local time and ended later on Friday morning.
"The troops responded with artillery fire and raids by helicopter gunships, killing 24 militants," he said.
"Seven of their bodies are in our possession."
The information is difficult to verify independently because access to the region is restricted.
Two other blasts
Elsewhere on Friday, a remote-controlled bomb attached to a cycle exploded on the outskirts of Quetta, in the southwest of the country, killing three police officers and wounding seven others.
The bomb was remotely detonated when a police van belonging to the state anti-terrorist force passed by.
The attack is being blamed on separatists who are fighting the army in Balochistan province.
Another blast, outside a school in the northwestern city of Peshawar, wounded a teacher and three children, police said.
Al Jazeera's Kamal Hyder, reporting from Islambad on the security post attacks, said the military "claims that they have inflicted heavy casualties on the attackers".
"Mohmand is a strategically important area because this is at the confluence of at least two provinces on the Afghan side of the border," he said.
He said that even though the Pakistani Taliban has taken responsibility for the attack, the military's view is that because of the scale of the attacks, the militants likely crossed over from neighbouring Afghanistan.
That 150 fighters were able to cross over unhindered is of major concern to the military, Hyder said. The US military has recently vacated many positions near the border in Afghanistan's northeast Kunar and Nangahar provinces.
Pakistan's Mohmand tribal region has long served as a sanctuary for rebels operating against US-led troops based across the border in Kunar province.
Mohmand also shares a border with another volatile Pakistani tribal district, Bajaur, where the Pakistani army conducted a year-long operation against Taliban fighters in 2008 and 2009.
Pakistani troops have scored major gains against pro-Taliban fighters in military offensives and operations since last year, however, attacks against security forces and civilians still continue.
More than 2,000 people have been killed in suicide and bomb attacks across Pakistan since the army stormed a mosque in capital Islamabad in 2007.
The army says its offensives in the Swat valley, South Waziristan and other tribal regions have weakened the Taliban, although analysts question their effectiveness because rebels tend to establish strongholds elsewhere.
Pakistani action against rebels on the border is seen as crucial to efforts to bring stability to Afghanistan, where US forces are spearheading one of NATO's biggest offensives against the Afghan Taliban.
However, Pakistan has often been criticised for not doing enough.
An intensifying uprising in Afghanistan has brought more pressure on Pakistan to go after rebels operating out of sanctuaries in remote enclaves on its side of the border.
Source: Al Jazeera and agencies