"Anonymous [has] taken down the website of the presidency of the Colombian republic", the group said on its Twitter page on Tuesday.
In other posts, the hackers claimed that they had also carried out cyber attacks on the Senate and National Army, leaking over 160 emails, names, and passwords.
Anonymous Colombia said the hacking attacks were a response to the crackdown on anti-tax hike protesters.
Just days ago, Colombian President Ivan Duque asked Congress to withdraw the draft tax reform and urgently discuss a new one amid nationwide protests. According to Colombia's human rights officials, over a dozen people have died amid the protests, including one police officer. The Ministry of Defence has reported more than 430 detentions and more than 800 injuries, both amid law enforcement and protesters.
Workers' strikes and public protests started in Colombia on Wednesday, with people walking out against the so-called Sustainable Solidarity Law, a tax reform bill presented earlier this month. Trade unions warned that the proposed reform would lead to at least 1.5 million workers having to pay new taxes.
Duque said prior to the protests that the new tax initiative, which was expected to help raise around $6.8 billion (about 2 percent of Colombia's GDP), would significantly contribute to efforts aimed at alleviating the negative economic effects of the coronavirus pandemic.
According to Defence Minister Diego Molano Aponte, Colombia's National Army has been providing temporary support to some cities affected by the ongoing protests in order to ensure the safety of citizens, the supply of essential goods, and the protection of transport and infrastructure.