Two Indian investigators have gone to Tehran to question Iranian suspects who they believe were involved in a bomb attack that wounded an Israeli diplomat's wife in New Delhi in February, police said Monday.

The investigators left for the Iranian capital last week after authorities there agreed to the Indian request to pursue the case, a police officer familiar with the case said on condition of anonymity as he was not authorized to talk to reporters.

New Delhi police have issued arrest warrants for three Iranians they believe planned or carried out the attack. They say the Iranians performed reconnaissance at the Israeli Embassy in May 2011 before returning to New Delhi early this year to plan the attack.

Police say two of the men left India before the attack but were previously in contact with an Indian journalist accused of conspiracy in the plot. The third left India after the attack.

One of the men, Housan Afshar, had also been in contact with Masoud Sedaghatzadeh, an Iranian who is accused of involvement in a blast in Bangkok a day after the New Delhi attack. Sedaghatzadeh was later arrested in Malaysia.

Syed Mohammad Kazmi, a 50-year-old freelance Indian journalist who reportedly worked for some Iranian news organizations, is the only person arrested in the five-month investigation into the New Delhi blast. He faces charges relating to terrorist activities, attempted murder and other illegal activities. If convicted, he could be sentenced to life in prison. He has denied all charges against him.

The Indian investigators are expected to return from Iran this week, the police officer said.

Meanwhile, the Indian Express newspaper reported that Indian investigators were also likely to visit the former Soviet republic of Georgia, where a bomb was discovered on an Israeli diplomat's car the same day as the New Delhi attack.

The next day, three Iranians accidentally blew up their house in the Thai capital.

Israeli authorities have said the similarity between all of the explosives linked Iran to all three incidents. Iran has denied any involvement.