A powerful blast targeting a police vehicle in a busy marketplace in Pakistan's restive southwestern Balochistan province on Monday killed at least four people, including two policemen, and wounded 18 others, in a fresh wave of attacks targeting security personnel.

The explosion occurred near a parked police vehicle next to Qandhari Bazar on Shahrah-e-Iqbal in the provincial capital Quetta, the Dawn newspaper reported.

No group has claimed responsibility for the attack, but previous such attacks have been blamed on Baloch insurgents and Islamic militants.

"The target was a police vehicle and the bomb was set off remotely,” SP Hameed Qambrani said.

He said the blast also damaged several vehicles parked outside shops in the area.

"The explosives were planted in a motorcycle," SSP Operations Captain (retd) Zohaib Mohsin said, adding that the injured also included women and children.

Four persons, including two policemen, were killed while 18 others were injured in the blast.

Mohsin said the injured were immediately transferred to Civil Hospital Quetta for medical treatment.

Civil Defence Director Rafu Mandokhail said that three to four kilos of explosives were used in the blast, while the explosive material was installed in a motorcycle.

TV footage showed a damaged vehicle of the police surrounded by a number of police personnel. Several ambulances were also seen leaving the site of the explosion.

Prime Minister Shehbaz Sharif condemned the blast in Balochistan’s capital city and offered condolences to the families of the victims.

A government spokesperson said that due to Eid festival security had been stepped up in all major markets and shopping malls of Quetta but in this case the police were the target of the remote bomb.

On Sunday, two policemen were killed and one injured when armed men opened fire on them in the city’s Kuchlik area.

There has been a lull in the terror attacks during the holy month of Ramzan but the peace was shattered with the attack on the policemen and the bomb blast in the busy Kandahari market.

Resource-rich Balochistan in southwestern Pakistan borders Afghanistan and Iran, But it is also Pakistan's largest and poorest province, rife with ethnic, sectarian and separatist insurgencies.

Baloch nationalists are active in the Balochistan province and often target the security forces and people from other provinces, especially Punjab.

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