NEW DELHI (Reuters) - Two men on a motorcycle shot dead on Monday a politician from the ruling party of Indian Prime Minister Narendra Modi in Uttar Pradesh, the second such killing in a week, prompting concern about lawlessness in the northern state.

Mr Omveer Singh, a local politician of the Bharatiya Janata Party (BJP), was riding a motorcycle to his hometown around 7am when two unidentified men pulled up and "shot him till he died", said local police official Kamal Singh.

Mr Singh shot back and wounded one of the assailants, but they managed to drive away. They did not take the two mobile phones, wallet and cash the politician had on him, said the policeman.

The shoot-out took place in Muzaffarnagar district, a flashpoint in western Uttar Pradesh in which some 60 people were killed in Hindu-Muslim riots last year. It was the latest in a surge of apparently unconnected violent incidents coinciding with a summer heatwave and the general election last month won by the BJP.

Mr Singh was killed three days after another BJP politician Vijay Pandit was shot dead in Noida, an industrial satellite city in Uttar Pradesh, India's most populous state.

Mr Pandit was standing outside his home on Saturday night when three men on motorcycles fired at him. His supporters said he was shot for campaigning against extortion rackets, the Indian Express reported.

An investigation has been launched, but the killings do not appear to be connected.

Uttar Pradesh, home to one in every six of India's 1.2 billion people, is one of the country's poorest and most crime-ridden states.

In one of the more heinous examples, two girls, aged 12 and 14, were raped and hanged from a tree there last month.

The state, ruled by the regional Samajwadi Party, was criticised for its lawlessness by opposition lawmakers in parliament on Tuesday.

Mr Singh, the police official in Muzaffarnagar, said Tuesday's attack might have been over money, as the politician's uncle allegedly owed 2 million rupees (S$42,220) to gangsters. "This was due to animosity between criminals and politicians," said Mr Singh.

Officials from the BJP said they had not heard about the killing. Mr Modi has not publicly commented on any of the episodes of violence.