KUALA LUMPUR: Malaysia’s premier called for calm on Saturday, as a fourth church was firebombed in the latest of a series of attacks on churches that has heightened ethnic tensions.

The unprecedented attacks risk dividing the mainly Muslim nation of 28 million people, which has significant religious minorities, and complicating Prime Minister Najib Razak’s plan to win back support from the non-Muslims before the next elections by 2013.

In a visit to one of the damaged churches on Saturday, Razak sought to quell tensions in the multicultural nations. “Islam prohibits us from insulting or destroying any other religions, either in the physical form or in the form of their worship places,” Najib said.

“All parties need to stay calm and should not act emotionally.”

The row, over a court ruling that allowed a Catholic newspaper to use the word “Allah” in its Malay-language editions, prompted Muslims to protest at mosques on Friday and sparked arson attacks on three churches.

While Najib visited the badly damaged Pentecostalist church and offered a government grant of half a million ringgit ($148,100) to maintain “a harmonious society,” church leaders said they wanted more concrete assurances of safety.

In the latest attack early Saturday, unidentified attackers flung a home-made petrol bomb at the Good Shepherd Lutheran Church in a suburb in Selangor state. The two-story bungalow sustained minor damage, church officials said.

Police said they have stepped up security at all places of worship but faced a manpower shortage. Inspector General of Police Musa Hasan told churches across the country to hire more security guards.

“Till today we are protecting the interests of other races besides championing those of the Malays,” Najib was earlier quoted as saying by state news agency Bernama.

“Don’t point fingers and say UMNO is racist...when churches are burned,” he said referring to his party, the United Malays National Organization (UMNO) that is the linchpin of the National Front that has ruled the country for 52 years.

But Malay-Muslims, including those in UMNO, fear the word could be used by Christians to proselytize to Muslims, which is already illegal in the Southeast Asian country.