Both attacks were claimed by Jamaat-ul-Ahrar, a splinter group of Pakistan's Tehreek-i Taliban (TTP) -- also known as the Pakistani Taliban -- which has killed scores of people in previous attacks targeting both groups in the country this year.
In the city of Mardan, in the northern province of Khyber Pakhtunkhwa, at least 13 people were killed and another 53 injured in an attack at the city's district courts Friday, District Police Officer Faisal Shehzad told CNN.
The attacker threw a hand grenade at the court gates, then blew blew himself up after security prevented him from entering, Senior Police Superintendent Shafiullah Khan said.
Four of those killed were lawyers, according to Amir Hussain, the president of the Mardan Bar Association.
There will be three days of mourning, during which time the courts will be shut, Hussain added.
Christian neighborhood attacked
Earlier in the day, a bystander was killed and three members of Pakistan's security forces injured when suicide bombers struck a Christian neighborhood near Warsak Dam on the outskirts of Peshawar, according to the Pakistan's military.
Pakistani police previously told CNN that four bystanders were killed and five were injured.
The attackers, four suicide bombers who were also equipped with arms and ammunition, entered the neighborhood after attacking a security guard early Friday morning, Peshawar Police Superintendent Kashif Zulfiqar told CNN.
Security forces responded, exchanging fire and killing the four assailants, according to a statement from the Pakistani military's Inter-Services Public Relations department (ISPR).
A house-to-house search is currently underway and the situation is under control, the ISPR says.
"We have enhanced the security of Christians establishments, schools, hospitals, colonies and churches," said Zulfikar.
Pakistan's Interior Minister Chaudhry Nisar Ali Khan congratulated security forces for their prompt response in foiling the attack.
Pakistan Prime Minister Nawaz Sharif condemned the latest attacks in a statement released by his office.
"These cowardly attacks cannot shatter our unflinching resolve in our war against terrorism," he said. "These receding elements are showing frustration by attacking our soft targets. They shall not get space to hide in Pakistan."
Claim of responsibility
Jamaat-ul-Ahrar, a group known for its bloody tactics aimed at soft targets, claimed responsibility for both attacks in an emailed statement.
"If Islamic law is not imposed across the country, such attacks will continue to be carried out," the statement said.
The group has been behind devastating attacks in Pakistan this year, including an Easter Sunday attack targeting Christians in the eastern city of Lahore which killed at least 69 people
, and a blast at a hospital in the western city of Quetta
last month, which killed 72 people, many of them lawyers.
Amnesty International's South Asia director Champa Patel said in a statement that the attackers were "seeking to undermine the rule of law by targeting both the people who defend it in court and the people it should protect."
The attacks were a "horrific reminder that Pakistan's authorities must do more to ensure vulnerable groups are protected," Patel said. "The authorities have a duty to protect the right to life, prevent human rights abuses, and hold perpetrators to account in fair trials without recourse to the death penalty or other human rights violations."
Christians make up only 2% of Pakistan's population, and face persecution from hardline Islamists, who want to see a strict interpretation of Islamic law take precedence in Pakistan's legal system.
Previous attacks on Christians in Pakistan have included a suicide attack in Lahore that killed at least 14 people in March last year,
and suicide attacks on a church in Peshawar in 2013 that killed more than 80 people.