Bomb attacks have killed 53 people in Pakistan, as British Prime Minister David Cameron called for tough action against terrorism during a visit to the capital.
In the two deadliest attacks on Sunday, a suicide bomber killed 28 people at a checkpoint near a Shi'ite Muslim mosque in the south-western city of Quetta, and a car bombing killed 17 in the north-west.
The combined toll marked the deadliest day for more than four months in the nuclear-armed state, which is battling home-grown extremism and is on the front line of the American-led war against al-Qaeda, AFP reports.
In Quetta, officials said a suicide bomber tried to get in a Shi'ite mosque in the congested Hazara town, a mainly Shi'ite community on the edge of the city, but was intercepted at a checkpoint.
Baluchistan provincial home secretary Akbar Hussain Durrani said the bomber blew himself up at a checkpoint set up by neighbourhood volunteers about 45 metres away from the mosque.
Quetta is one of the most volatile cities in Pakistan, gripped by Taliban violence, a separatist Baluch insurgency and a growing number of attacks on the Shi'ite minority. Hazara Town in particular has been a flashpoint for attacks on Shi'ites and the minority Hazara ethnic group.
Earlier, while Mr Cameron was holding talks with new Prime Minister Nawaz Sharif in Islamabad, a car bomb targeted a security force convoy on the outskirts of Peshawar, not far from the semi-autonomous tribal belt where Taliban and al-Qaeda-linked groups have bases.
Police said most of the victims were civilians because the bomb targeting the Frontier Corps convoy exploded in a bustling market area.
There was no immediate claim of responsibility, but the Pakistani Taliban frequently targets security forces as part of a seven-year domestic insurgency that has killed thousands of Pakistanis.
Speaking in Islamabad, David Cameron said the battle against terrorism needed "a tough and uncompromising security response" as well as investment in education and measures to ease poverty.
Nawaz Sharif said Pakistan was "resolved to tackle the menace of extremism and terrorism with renewed vigour and close cooperation with our friends".