Authorities in Malaysia arrested 14 people Wednesday for supporting an upcoming mass rally calling for electoral reform.

The arrests in northern Perak state bring to nearly 100 the number of people detained since last week for promoting the July 9 demonstration in Kuala Lumpur. The arrests include 30 members of the Socialist Party of Malaysia, who were detained Saturday after police said they found leaflets and t-shirts promoting an outlawed communist party on their bus.

The group has been charged with trying to wage war against Malaysia's constitutional monarch.

The rally is being planned by a coalition of opposition parties and activists calling itself “Bersih,” which is the Malay-language word for “clean.” The group is calling for a more transparent voting process ahead of national elections widely expected will be held by next year.

The government has declared the rally illegal and has warned people not to attend.

Bersih attracted 30,000 people to a massive rally in 2007, which police eventually broke up with tear gas and water cannons. Malaysia's opposition coalition has made major gains against the ruling party since 2008, ending its two-thirds majority in parliament and gaining control of a handful of states.