An engineer who was detained when he tried to forcibly make his way into the prime minister's residence was remanded to a mental institute by a court in Delhi on Wednesday.

"Where is Mr Prime Minister? I need to speak to him immediately," engineer Sampat Kumar, a bachelor of technology from a US university, told guards who challenged him when he appeared at the gate of 7 Race Course Road residence of Prime Minister Manmohan Singh on Tuesday night.

He then started forcing his way into the residence, giving a tough time to the guards who did not want to be rude to him, officials said.

Kumar came to the high-security residence in a taxi and asked the guards where the prime minister was. He said he needed to speak to the prime minister about the state of affairs of the country, which were not good.

After failing to persuade him to leave, the guards detained him and informed police and Central agencies, who whisked Kumar away for questioning.

After quizzing Kumar, officials were convinced that he had some mental problem. He was produced in a court on Wednesday that remanded him to a mental institute.

A background check revealed that Kumar had been jobless for over a year after completing his studies.

He claimed during questioning that he had written several letters to the prime minister to apprise him about problems affecting the country, but had not got any response, officials said.