The latest attack, on an Evangelical Christian church,
caused limited physical damage -
just a burned door and a charred entranceway.
But the political implications may be more serious.
Tensions have flared after Malaysia's High Court
ruled that a Roman Catholic newspaper,
the Herald, was permitted to use the word "Allah"
to describe God in its Malay language editions.
Muslim groups argue that
Christians using a word so closely associated with Islam
could be a ploy to win converts.
Christians make up around 9%
of the population in the majority Muslim state.
Most non-Muslims are ethnically Indian or Chinese.
The row over the use of the word "Allah"
has exposed deep resentments
over the treatment of minorities
and freedom of religion in Malaysia.
A government minister told foreign diplomats on Monday
the church attacks were the work of extremists.
"These were not just attacks on houses of worship" he said,
"these were attacks on the values
and freedoms all Malaysians share."
Under the slogan "One Malaysia",
the government has made racial harmony a central policy.
Its commitment to that policy
is now being severely tested.