Pakistan says it is time to put an end to accusations and move forward in a cooperative relationship with neighboring Afghanistan, after Afghan authorities blamed Pakistan-based militants for a massive suicide attack.

Pakistani foreign office spokesman Abdul Basit told reporters Thursday that blaming Pakistan for “unfounded events” creates problems, and Islamabad wants a relationship that is free of recrimination.

The comments came a day after Afghan President Hamid Karzai vowed to confront Pakistan about a suicide attack targeting Shi'ite Muslims in Kabul, which killed 55 people on Wednesday.

Mr. Karzai said he blames Lashkar-e-Jhangvi, a Sunni extremist group affiliated with al-Qaida that is responsible for a number of attacks against Shi'ites in Pakistan.

Pakistani authorities have been hunting members of the outlawed group for years. Pakistani Interior Minister Rehman Malik on Wednesday pledged to take action if Afghan authorities offer any proof to support their claim. But he also warned against making “baseless accusations.”

Tuesday's blast in Kabul took place near the Abul Fazel shrine as worshippers gathered on Ashura, the holiest day of the Shi'ite Muslim calendar. A second explosion killed four people at a shrine in the northern city of Mazar-e-Sharif.

The Taliban condemned the killings, calling them “cruel and indiscriminate” and blaming them on the “invading enemy.” The group also denied any involvement in the attacks, but Lashkar-e-Jhangvi appears to have claimed responsibility for the Kabul carnage.

Experts say the attacks, which came in the aftermath of an international conference to discuss Afghanistan's future following the withdrawal of coalition combat troops by the end of 2014, underscore the importance of what was agreed in Bonn — that all countries in the region need to cooperate in securing long-term stability for Afghanistan.

Pakistan boycotted the conference in protest of a NATO cross-border attack that killed 24 Pakistani troops on November 26.