QUETTA, Pakistan -- A suicide bombing near a market in southwestern Pakistan killed five people and wounded at least 20 on Saturday, hours after a powerful bomb went off at a bus station in the country's northwest, killing five and wounding three, police said.

The suicide bomber struck in Quetta, in the city's Shiite-dominated neighbourhood of Hazara Town, an area that has seen bombings and suicide attacks in the past, said police chief Abdur Razzak Cheema.

The bomber was approaching a local market when police stopped him at a checkpoint, at which point he detonated his explosives, said Cheema. A woman was among the three killed, while two women and four children were among the wounded.

The blast was so powerful that the severed head of the bomber was later found on the premises of a girls' school nearby, said Bostan Ali, a local resident. The explosion also partly damaged the outer wall of the school and two vehicles, Ali said.

Also Saturday, a roadside bomb exploded near a livestock market in Quetta, wounding five people, police officer Mohammed Ishaq said.

The city is the capital of Baluchistan province, where the al Qaeda-linked Lashker Jhangvi group operates, along with Baluch separatist and nationalist groups.

No one claimed responsibility for the suicide bombing, though Lashker-e-Jhangvi has in the past claimed attacks on Shiites in Quetta.

Earlier Saturday, in the northwestern town of Kohat, a powerful, remote-controlled bomb struck a moving bus as hundreds of passengers were gathered at the station trying to leave for various destinations to go celebrate the major Muslim holiday of Eid al-Adha, said Ishtiaq Marwat, a senior police officer.

Pakistan will start celebrating the holiday on Monday, though most Muslims in the world began observing it on Saturday. This is because Eid follows the Islamic lunar calendar, which depends on the sightings of the moon.

Footage from Pakistani news channels showed the damaged bus. Marwat said five people were killed and three were wounded in the bombing.

No one immediately claimed responsibility for the attack in Kohat, about 50 kilometres southwest of Peshawar, the capital of Khyber-Pakhtunkhwa province. Kohat has been the scene of sectarian attacks in recent years, most of them blamed on Pakistani Sunni militants.

Meanwhile, anti-government demonstrations continued in the capital, Islamabad, despite the approaching Eid holiday. The demonstrators, led by opposition politicians Imran Khan and Muslim cleric Tahir-ul-Qadri converged on the capital in mid-August, demanding Prime Minister Nawaz Sharif's ouster over alleged fraud in last year's election.

Sharif has told the parliament that the protests have damaged the image of Pakistan in the world and also caused huge economic losses in the country.