Student groups in Taiwan Tuesday accused the government of trying to clamp down on their freedom to protest against a planned sale that they believe will make the media more Beijing friendly.

The students reacted angrily after the education ministry sent a notice to 37 universities expressing "concerns over the health of students" for joining street protests -- despite bad weather -- against Hong Kong-based Next Media's plan to sell off its Taiwanese assets.

"We are very healthy and we want to defend Taiwan's freedom of speech and democracy. It's the education ministry trying to suppress student movements that is sick," the Youth Alliance Against the Media Monster said in a statement.

Hung Chung-yen, a student leader of the alliance, told AFP: "That notice was mindful of the period when Taiwan was under martial law and people's freedom of expression was suppressed."

Taiwan's education minister Chiang Wei-ning on Monday apologised for the issuing of the notice and ordered schools not to keep tabs on student protest activities.

Next Media, controlled by vocal China critic Jimmy Lai, last week signed agreements with "respective buyers" to sell off the Taiwan editions of Apple Daily and Next magazine as well as Taiwan Sharp Daily and Next TV.

Concerns have been raised the deals could create a pro-China media monopoly. Sources have identified one potential buyer as Tsai Eng-meng, who has substantial business interests in China.

Such issues are still sensitive in Taiwan more than six decades after it split from China following a civil war. Beijing views the island as part of its territory awaiting reunification, through force if necessary.