The bomber entered the Imambargah, used for religious services, in the remote Chalgari area of Kachhi district at the time of evening prayer and exploded his explosive-laden vest.
"At least 10 people were killed and a dozen others were wounded after a suicide bomber blew himself up at the shrine," Balochistan home minister Sarfaraz Bugti said.
Bugti said there were six children between 10 and 12 years old among the dead and that some women had also died.
The explosion was heard in a wide area and shattered windows in the nearby vicinity.
Also Read
Security forces reached the blast site and cordoned off the area.
Police said since the village was in a remote area the rescue workers and paramedical officials were finding it difficult to shift the injured to the only health unit in the area.
"They are now being shifted to Sibi," Bugti said.
A local administration official said the suicide bomber appeared to be about 18 years old and was wearing a woman's burqa.
It was the first major attack that targeted the minority Shia Muslims in the holy month of Moharram when they organise special prayers and take out processions to observe the martyrdom of Hussain Ibne Ali, the grandson of the Prophet.
Sectarian violence in particular that carried out by Sunni militants against minority Shia has claimed thousands of lives in the country over the past decade.
Balochistan has been rocked due to violence by extremists and ethnic Baoch militants.
Earlier this week, at least 10 people, mostly daily wage workers were killed in an explosion in a passenger bus in the provincial capital Quetta.