In Pakistan, a suicide bomb attack at a Shiite Muslim mosque has killed at least four people and injured several others. In the past two weeks violence against religious groups has killed 80 people.

The bombing took place in the eastern city of Lahore. Witnesses say an unidentified man blew himself up when security guards tried to stop him from entering a mosque for Shiite Muslims where scores of people were offering evening prayers. The victims included the suicide bomber.

On-going sectarian violence between majority Sunni and minority Shiite Muslims has killed dozens of people in Pakistan this month.

On Saturday, two prominent Sunni Muslim clerics were gunned down in the southern city of Karachi, triggering protests from their followers. Those killings followed two deadly attacks on religious gatherings in central Pakistan, in which more than 70 people from Sunni and Shiite sects were killed.

Meanwhile, authorities say talks aimed at securing the release of two kidnapped Chinese engineers are progressing well.

The Chinese men, Wang Ende and Wang Peng, and their two local security guards were kidnapped Saturday in the remote South Waziristan region near the border with Afghanistan.

Pakistani military forces are engaged in major anti-terror operations in the area, where fugitive members of the al-Qaida terror network are believed to be hiding. Officials say the kidnappers are linked to al-Qaida.

"We are hopeful that these Chinese engineers will be released soon," said Sheikh Rasheed Ahmed, Pakistan's information minister. "We are holding talks with them [the kidnappers] and they have demanded release of two [of their] people so we have asked them to give us their facts and figures."

Authorities say the kidnappers have threatened to kill the Chinese unless their demands are met. Authorities in China have urged Pakistan to do all it can to rescue the Chinese engineers.