Deutsche Lufthansa AG and Alitalia SpA said they’ll recommence flights to Tokyo tomorrow after diverting services to southern Japanese cities amid concern that the earthquake and tsunami would lead to radioactive fallout.

Lufthansa, the first major carrier to reroute flights, will resume services to Tokyo’s Narita airport while continuing to have crews spend the night in Seoul, spokesman Peter Schneckenleiter said today by telephone. Alitalia will fly to the Japanese capital from Milan and Rome with a “technical” stop in the southern city of Osaka, the Italian company said.

Lufthansa diverted Tokyo flights to Osaka and Nagoya within days of the March 11 quake, citing the risk of fallout from the Fukushima Dai-Ichi nuclear plant, with Alitalia following suit on March 16. While the risk of meltdown may have receded, leaks remain a threat and engineers were evacuated from two reactors today as smoke was seen rising from one of the buildings. Tokyo authorities also say tap water may be unsafe for infants.

“It’s a competitive disadvantage not to be flying to Tokyo if everyone else is doing it,” said Per-Ola Hellgren, an analyst at Landesbank Baden-Wuerttemberg in Stuttgart with a “buy” rating on Lufthansa. “The perception of nuclear power is very negative in Germany and Lufthansa probably felt there was some pressure not to be seen to take any unnecessary risks. But they’ve been checking planes returning from Japan for traces of radiation and as far as I have seen nothing has been found.”

’Stable, Secure’

Lufthansa will deploy Airbus SAS A340 wide-body planes for flights to Tokyo from Frankfurt and Munich, it said in a statement. Direct flights to Nagoya and Osaka, which were part of the original timetable, will continue, it said.

“Lufthansa is once again offering passengers a stable and secure service to the Japanese metropolis,” the carrier said.

Alitalia didn’t comment on its reasons for returning to Tokyo in a statement issued after markets closed yesterday.