Asian football chief Mohamed Bin Hammam on Tuesday declined to reveal whether he would challenge Sepp Blatter for the FIFA presidency but promised to make an announcement this week.

The president of the Asian Football Confederation (AFC) has dropped repeated hints in the past two months that he may stand, writing on microblogging site Twitter on Monday that he will "clarify" his position on Friday.

In a gym at Kabul's main stadium, where the Taliban used to publicly execute women accused of adultery, female Afghan boxers hoping to make it to the London 2012 Olympics are practicing their jabs.

Some wearing headscarves, all in tracksuits, the slightly built young women pummel four heavy old punchbags hard, moving fast and light on their feet while their male trainer barks instructions.

German, Spanish and Italian league leaders Borussia Dortmund, Barcelona, AC Milan made uncharacteristic slip-ups at the weekend, with varying consequences to their title hopes.

Bundesliga trailblazers Dortmund fell to only their third defeat of the season, a 1-0 reverse to Hoffenheim; Barcelona were held 1-1 by Sevilla, and Milan suffered the same fate against Bari.

Former champions Jelena Jankovic and Kim Clijsters cruised into the third round by posting straight-set victories Friday at the WTA and ATP Masters 1000 event.

World No. 2 Clijsters, who won in 2005 and 2003, swept past Russian Alla Kudryavtseva with a dominating 6-2, 6-0 victory in the second round of the hard-court tournament.

Argentina's David Nalbandian will undergo surgery for a hernia problem and a torn adductor muscle on Thursday and will be out of action for two months, a member of his entourage said Wednesday.

The world number 19 aggravated the problem playing in the Davis Cup last weekend which saw the South Americans advance past Romania 4-1 to the quarter-finals of the World Group.

Real Madrid hopes to offload its injury-plagued Brazilian star Kaka in the summer close season, although he still has four years left on his contract, a Spanish sports daily said Wednesday.

The 28-year-old midfielder, signed from AC Milan in 2009 for 65 million euros, underwent surgery on his left knee on August 5 and only returned to training in December.

Barcelona have defensive worries ahead of Tuesday's Champions League showdown with Arsenal which midfielder Seydou Keita has described as crucial for their season.

Keita scored the only goal as Barcelona kept up the pressure at the top of La Liga with a 1-0 win over Zaragoza at the weekend and now they turn their attention to Europe where they must overturn a 2-1 defeat at the Emirates to progress to the quarter-finals.

Lebanese Basketball team Al-Riyadi seeks to move on to the Final round of West Asia basketball league when they meet Iranian team Mehram today at 6pm in Saeb Salam Hall.

Al-Riyadi is heading into the game with high spirits, despite the absence of their injured star Jean Abdel Nour.

Kenny Dalglish has urged Liverpool to use the momentum from their impressive 3-1 win over Manchester United to spark a successful end to the season.

Dalglish was able to savor the best result of his second spell in charge at Anfield on Sunday as Dirk Kuyt's hat-trick put United to the sword in convincing fashion.

Serena Williams' absence from tennis could stretch to almost a year after two new health scares — a blood clot in her lungs followed by a hematoma — have added to her injury woes.

Her agents confirmed Wednesday that Williams was diagnosed with a pulmonary embolism last week and later needed treatment for a hematoma. The 13-time Grand Slam champion hasn't played an official match since winning Wimbledon last July because of a foot injury she sustained not on the court but at a restaurant.