Police sources told Aljazeera's correspondent in Pakistan the bomber was killed when he detonated explosives he was carrying during communal prayers on Saturday.
Abd al-Rahman Tishudi, spokesman for Pakistan's information ministry, said: "No group has claimed responsibility for the attack and Pakistani authorities have not accused any of being involved in the attack."
And Shaikh Rashid Ahmad, Pakistan's minister of information, said the situation at the scene was now "under control".
The attack came during the holy month of Muharram, the first of the Islamic year.
The month is particularly significant for Shia Muslims, who commemorate the martyrdom of Prophet Muhammad's grandson, al-Husyain.
Sectarian violence between Sunni and Shia Muslims has claimed thousands of lives in Pakistan over the past decade, with attacks on mosques a regular occurrence.
In recent months police have arrested dozens of people in an effort to prevent hostilities between majority Sunni and minority Shias.
Police and paramilitary troops have already been put on alert before Muharram, which started on 22 February.
Drive-by shootings in the port city of Karachi killed dozens of people, mostly Shias, last year.
Hardliners in both communities accuse each other of corrupting the true teachings of Islam.
Pakistan's Afghan border is a
notoriously lawless tribal area
Meanwhile, 11 people were killed and seven others injured when Pakistani soldiers opened fire at two cars in the restive tribal region bordering Afghanistan.
"The soldiers suspected that al-Qaida and Taliban members were travelling in the cars in an attempt to flee to Afghanistan," Aljazeera's correspondent in Pakistan quoted official sources and witnesses as saying.
The dead were later proved to be citizens of the Angkor Eda area, he added.
Sensitivities are running high in the conservative region after Pakistan's army launched a raid on suspected fighters earlier this week.
And in a separate incident across the border in eastern Afghanistan, US troops shot dead a fighter, the American military said.
The troops exchanged fire with several attackers on Wednesday near an American base at Orgun in Paktika province, 175km south of Kabul.
No American or allied Afghan soldiers were wounded, Lt Col Bryan Hilferty, a military spokesman, said on Saturday.
American and allied occupation forces have been coming under regular fire in their bases and on patrol, in Afghanistan.