Iran media on Wednesday slammed a proposal made by world powers seeking to scale back Tehran's nuclear program as "unbalanced" and failing to address other outstanding issues.

State media, including the Islamic Republic News Agency, all called the proposal made to Iranian officials in talks in Baghdad "outdated, not comprehensive and unbalanced."

A strong 6.1-magnitude undersea earthquake rattled northeast Japan at around midnight on Wednesday, but there were neither immediate reports of damage nor tsunami alert.

The quake hit at 1502 GMT at a depth of 40 kilometers (25 miles), the U.S. Geological Survey said, 120 kilometers from the city of Hakodate, on the northern Hokkaido island.

Britain's Supreme Court said on Wednesday it will give its judgment in the case of WikiLeaks founder Julian Assange's long-running fight against extradition to Sweden on May 30.

The court announced the date in a statement on its website, saying the judgment would start at 9:15 am (0815 GMT) next Wednesday and would last around 10 minutes.

Russia said on Wednesday that Iran was ready to hold serious talks on its nuclear program that could lead to a gradual lifting of sanctions in exchange for broader transparency from Tehran.

"We have a clear understanding... that Iran is ready to agree on concrete actions," Foreign Minister Sergei Lavrov told reporters, without elaborating.

Afghan intelligence agents on Wednesday arrested five suicide bombers with hundreds of kilos of explosives near Kabul international airport.

"We have arrested five suicide attackers with 560 kilograms of explosives in a minivan just near the gate of Kabul international airport," National Directorate of Security (NDS) spokesman Lutfullah Mashal told Agence France Presse.

Three Kurdish rebels were killed Tuesday in a gunbattle with security forces in southeastern Turkey, Turkish media said Wednesday.

The firefight erupted Tuesday around 16:05 GMT in a rural area near the town of Ovacik in Tunceli province; Anatolia news agency cited the provincial governor's office as saying.

Two commuter trains collided head-on in Warsaw Wednesday, injuring two people, on a stretch of railway near Poland's new national stadium where the Euro 2012 football championships kick off in June.

The crash caused major train delays, Polish State Railways spokesman Miroslaw Siemieniec said, according to PAP news agency. He said it was not yet known why both trains were travelling in opposite directions on the same track.

Israeli Defense Minister Ehud Barak urged world powers not to waver in Wednesday's key talks with Iran, warning that any failure to halt enrichment would see Tehran obtain a nuclear weapon.

"In Baghdad, we must watch out that partial concessions do not allow Iran to avoid a tightening of sanctions," he said, as a second round of talks between Tehran and six world powers got underway in the Iraqi capital.

Russia on Wednesday staged the first successful test-launch of a new intercontinental ballistic missile capable of breaching defense systems now being developed by NATO, a military spokesman said.

The announcement came less than a week after NATO formally activated the first stage of a missile defense shield whose deployment Russia has bitterly opposed out of fears that it may target its own vast nuclear arsenal.

Iranian President Mahmoud Ahmadinejad will visit Beijing next month, a spokesman for the Islamic republic's embassy said Wednesday, amid an escalating crisis over Tehran's nuclear program.

Ahmadinejad will be in the Chinese capital for a meeting of the Shanghai Cooperation Organization, a Central Asian grouping headed by Beijing and Moscow, said spokesman Mohammed Ali Ziaei.