Fifteen people were killed and more than 30 others were wounded in a suicide bombing near a political rally in Pakistan, authorities said.

Hundreds of members of the Balochistan National Party (BNP) had gathered for a rally at a stadium in Quetta, the capital of restive Balochistan province, when a bomb exploded in the parking area on Tuesday night.

Provincial authorities said on Wednesday that the death toll had risen to 15. The Islamic State militant group said it carried out the attack.

Balochistan, which borders Afghanistan and Iran, is the country's largest and poorest region. Its residents also face regular and often deadly attacks from the Islamic State and separatist groups.

The suicide bomber could not reach the rally venue due to tight security, Balochistan health minister Bakht Muhammad Kakar said, according to Pakistani network Geo News.