Pakistan has deployed army and paramilitary forces to protect Sri Lanka's cricket team after a deadly suicide bombing in Islamabad raised security concerns during their ongoing tour.

Pakistan's army chief Asim Munir had assured Sri Lankan defence minister Pramitha Bandara Tennakoon of the team's safety, interior minister Mohsin Naqvi told parliament in a live televised transmission on Thursday.

"Our army and paramilitary are deployed for the Sri Lankan team's security," he said.

Naqvi also said the Sri Lankan players had expressed serious concerns about staying in Pakistan following the bombing, but those had been addressed.

"The Sri Lankan president personally spoke to the team yesterday and encouraged them to play," Naqvi added.

The cricket stadium and the hotel where the Sri Lanka team is staying are both less than 10km from the site of the bombing.

The Sri Lanka Cricket Board said on Wednesday that several players had asked to return home after the blast, the first attack on civilians in the capital in a decade.

The board instructed the team to stay, saying Pakistan's authorities had given "foolproof" security guarantees.

The board said players who opted to return early would face a formal review to assess their actions.

A suicide bombing outside an Islamabad court on Tuesday killed 12 people and wounded 27, one of the capital's deadliest attacks in years.

Militants also stormed a military-run school in Wana, killing three people before security forces rescued students and shot the assailants dead.

Pakistan blamed militants based in Afghanistan, alleging Indian support, accusations Kabul and New Delhi denied. Defence minister Khawaja Asif said the attacks had put the country in a "state of war".

The violence revived memories of the 2009 Lahore attack on Sri Lanka's team, which halted international cricket in Pakistan for nearly a decade.

Six players were injured in the assault, forcing Pakistan to play home matches in the United Arab Emirates for years.

Security in major cities has since improved, allowing international teams to return. Test cricket in Pakistan resumed when Sri Lanka toured in 2019.

Sri Lanka are playing a three-match one-day series in Rawalpindi, near Islamabad, followed by a Twenty20 tri-series involving Zimbabwe.