Islamabad, Pakistan (CNN) -- A suicide bombing and a gunfight in Pakistan's tribal region Friday killed more than 50 people, government officials said.
The incidents occurred in the Khyber Agency, one of several districts of northwestern Pakistan's volatile tribal region bordering Afghanistan. Militants have a strong presence in Khyber and other regions along the Afghan-Pakistani border.
A suicide bomb at the entrance to a mosque in Nahqi killed at least 20 people, said Jamilur Rehman, a senior official of Khyber. The suicide bomber detonated his explosives at the end of Friday prayer, he said. There has been no claim of responsibility.
At least 22 people were injured, Rehman said.
Separately, fighting at a Khyber checkpoint left 10 security personnel and 23 militants dead, said Mutahir Zeb Khan, another government official.
Militants sparked a five-hour gun battle when they attacked the checkpoint, Khan said. Authorities believe the fighters were part of Lashkar-e-Islam, a militant group that operates in the region.
Journalist Zahir Shah Sherazi contributed to this report.