Insurgents in Iraq have intensified their campaign of pre-election violence, killing two aides to the country's highest Shi'ite authority, Grand Ayatollah Ali al-Sistani.

Sheikh Mahmoud al-Madai'ni, his son and four bodyguards, were gunned down Wednesday as they left evening prayers south of Baghdad in Salman Pak. Another aide was found dead in the ayatollah's office in Najaf.

Ayatollah al-Sistani is not a candidate in the January 30 polls, but he supports the United Iraqi Alliance, a mainly Shi'ite coalition that is likely to win a large number of seats in the national assembly.

Meanwhile, gunmen opened fire on a minibus outside a Baghdad hotel Thursday, killing six people and kidnapping a Turkish businessman. And near the town of Baquba, police say three people were killed and at least 13 others were hurt in a car bombing outside a Shi'ite mosque.

Some information for this report provided by AFP, AP and Reuters.