QUETTA, Pakistan (AP) — A suicide bomber targeted a Shiite mosque in southwest Pakistan on Thursday, killing at least 10 people and wounding several others, a government official said.

Provincial home minister Sarfraz Bugti said the attack took place in the district of Sibi, about 200 kilometers (120 miles) southeast of Quetta, the capital of Baluchistan province. He said the suicide attacker entered the mosque as Shiites were holding a gathering ahead of the Ashoura, a key religious event.

Six children were among those killed, Bugti said. The male suicide bomber was wearing a woman's head-to-toe burqa dress to deceive guards, he said.

No one immediately claimed responsibility, but suspicion fell of Sunni extremists who have been blamed for previous such attacks.

The latest attack came ahead of Ashoura, a 10-day ritual during which Shiites commemorate the death of Imam Hussein, the grandson of the Prophet Muhammad. Pakistan has boosted security for Ashoura, when minority Shiite Muslims hold public rallies despite threats from Sunni extremists who consider them to be heretics.

Meanwhile, Pakistan's army said Thursday airstrikes overnight killed 21 "terrorists" in the villages of Tirah and Rajgal in the Khyber region.

The military provided no further details about Wednesday's strikes, and the information could not be corroborated as journalists are barred from tribal areas. Pakistan has been waging a military offensive against al-Qaida and other militants in the North Waziristan province bordering Afghanistan since June 2014.

Pakistan's Prime Minister Nawaz Sharif is currently visiting the United States and will meet with President Barack Obama later on Thursday.

Associated Press writer Munir Ahmed in Islamabad contributed to this report.