LAHORE, Pakistan (CNN) -- Suicide bombers struck twice in northwestern Pakistan on Sunday killing at least 31 people in two separate attacks as the death toll from a weekend of violence continued to mount.
At least 14 died as a joint police-army convoy was hit by two suicide bombers and a roadside bomb early on Sunday as it was traveling through the mountainous region near the Pakistani-Afghani border, an army spokesman told CNN.
In a seperate incident, 17 police officers and new recruits died when a bomber detonated explosives at a police headquarters in the town of Dera Ismail Khan, an officer told The Associated Press.
The attacks came one day after 24 soldiers were killed and dozens more injured when a suicide car bomber crashed into two army vehicles near the Afghan border.
Maj. Gen. Waheed Arshad told CNN that 11 of the victims of Sunday's first attack were security personnel and three were civilians. In addition, 39 people were wounded -- 28 of them critically.
The casualties occurred when two suicide bombers rammed their explosives-laden vans into the 40-vehicle convoy. A roadside bomb also exploded simultaneously during the suicide bomber attacks.
The blasts were so strong six houses and several shops were damaged.
The convoy, which included about 40 vehicles, was traveling in Swat -- an area in North West Frontier Province, Arshad said.
In Dera Ismail Khan, the bomber struck as recruits were being tested to join the force, a police officer, Gul Afzal Afridi, told AP.
"It was a suicide bombing and the attacker mingled among the scores of people gathered for the test and physical examination," Afridi said.
No one claimed responsibility for Saturday's suicide attack in the town of Miran Shah, but Islamic militants -- including supporters of the Taliban and al Qaeda -- are active in the lawless border region of North Waziristan.
Pakistan's government has deployed thousands of troops to the northwest in a bid to defuse extremist calls for a holy war following last week's bloody end to a siege at the Red Mosque in Islamabad, where more than 100 people were killed including a pro-Taliban cleric, Abdul Rashid Ghazi.
"With help from local tribal elders, we are trying to ensure that militants lay down their arms and stop issuing calls for jihad against the government," a senior military official told The Associated Press.
Also on Saturday, two soldiers were injured when suspected militants detonated a bomb in the town of Bannu, a local police chief told AP. In Peshawar, two anti-tank mines attached to a timing device were discovered in a car parked in front of the military-affiliated Askari Bank.
At least 67 people have died in bombings and shootings since the Red Mosque siege began on July 3, AP said. E-mail to a friend