TOKYO (Reuters) - The Japanese government scored higher public approval ratings for Prime Minister Shinzo Abe's handling of the hostage crisis involving two Japanese captured in Syria and killed by Islamic State in Iraq and Syria (ISIS) militants, polls published this week showed.

Japan's biggest daily Yomiuri found that support for Mr Abe's government had risen to 58 per cent from 53 per cent in January. The paper surveyed 1,054 people by telephone on Friday and Saturday for the poll, which was the first since the hostages were killed.

A separate poll released by Kyodo on Saturday also showed an increase in support for Mr Abe. More than 60 per cent of respondents said they approved of the government's response to the hostage crisis.

Mr Abe has vowed to step up humanitarian aid to the militant group's opponents in the Middle East and bring the killers to justice. The gruesome executions and the recordings of journalist Kenji Goto released by the militant group captured the attention of the pacifist nation. A majority of the Japanese surveyed by both Yomiuri and Kyodo agreed with Japan's plan to continue humanitarian aid to regions affected by ISIS.

In terms of how Japan should respond to the ISIS threat, 57 per cent of people polled by Kyodo said any response should be non-military.

Mr Abe's popularity had slipped in more recent polls after the resignations of key Cabinet ministers and due to Japan's floundering economy, though his party won a landslide snap election in December.

ISIS militants beheaded Mr Goto last month, a week after the group released footage appearing to show the beheaded body of another Japanese hostage Haruna Yukawa.

The killings of the hostages have fanned calls to allow Japan's long-constrained military to conduct overseas rescue missions as part of Mr Abe's push for a more muscular security posture.