In the first attack, three soldiers were killed when a security forces convoy going from Razmak in North Waziristan tribal region to Bannu in Khyber-Pakhtunkhwa province was targeted with a roadside bomb.
Militants also fired rockets at the convoy, security officials were quoted as saying by TV news channels.
Three soldiers were killed and as many injured in the attack, officials said.
Security forces imposed curfew in the area and launched a search operation to trace the attackers.
In the second attack, a soldier was injured when a security forces convoy was targeted with a roadside bomb at a check post in Mirali area of North Waziristan.
Two security personnel were injured in the attack, TV news channels reported.
No group claimed responsibility for the attacks.
US officials describe North Waziristan as a safe haven for Taliban and Al Qaeda elements.
Meanwhile, two policemen were killed when gunmen riding motorcycles opened fire on a police vehicle in the Patel Para area in Karachi.
TV channels, however, reported the death of three policemen in the attack.
"Armed men on motorcycles opened fire on a police mobile which was parked there for snap checking," SSP Imran Shaukat said.
Two hand grenade attacks were also carried out in two different parts of Lyari area in the city, killing two people, including a 11-year-old boy, and injuring 10 others.
A police official in Lyari said that two persons were killed and nine others injured when miscreants lobbed hand grenades in a lane near Gabol Park.
"The injured included three women and a child," he said.
A similar attack was carried out in Hangu lane of Lyari area, injuring three people.
Police also recovered two dead bodies from Bihar colony in Lyari area, while two persons were killed in firing in Garden and Gulshan-e-Iqbal areas.
Police recovered the dead bodies of a woman in Malir and a man in Orangi town.
The Mutthaida-e-Qaumi Movement (MQM), the single largest party in Karachi, has been holding protest rallies and press conferences to highlight the disappearance and killings of their workers and sympathisers in Karachi.
