Carbomb explosion followed by heavy gunfire hit the gate of the presidential palace in the Somali capital Mogadishu, and Somali President Hassan Sheikh Mohamud is safe, police and the UN office in the Horn of Africa country said Friday. UN Somalia envoy Nicolas Kay said in a twitter post that Somali president was unharmed and condemned the attack on the presidential palace known as The Villa Somalia. "President just called me to say he's unharmed. Attack on Villa Somalia had failed. I condemn strongly this terrorism," Kay tweeted. The carbomb went off at one of the gates of the presidential residence before several heavily armed gunmen tried to storm it but was confronted by presidential guards, police officer Mohamoud Yonis told Xinhua. "Firefight broke out between the guards and the gunmen who were quickly neutralized by our forces," Yonis said, but did not say if there were any casualties. This is one of the most serious attacks by the Al-Qaida linked terror group Al-Shabaab in Mogadishu in recent years. Al-Shabaab last launched a suicide bomb attack near the gate of the Somali prime minister's office at the presidential palace in January 2013, killing a soldier and injuring two others.