Mirpur (Bangladesh), July 8 (IANS): Bangladesh's limited overs captain Mashrafe bin Mortaza has no clue why his batsmen are failing to blunt the threat posed by South Africa's spin attack.

The Proteas completed a clinical Twenty20 International series sweep beating the hosts by 31 runs in the second match at the Sher-e-Bangla National Stadium here on Tuesday, reports bdnews24.com.

The hosts' batsmen were put to the sword by South Africa's second-string bowling attack in both the matches.

In the first, Aaron Phangiso and JP Duminy returned with 3/32 in eight overs between them. On Tuesday, Phangiso and debutant leg spinner Eddie Liei took three wickets each. Although Duminy went wicketless, he conceded only 26 runs in his four overs.

In their last two series' against India and Pakistan, the batsmen handled some world-class spinners quite well. But they have been completely dominated by a mediocre Proteas spin attack.

"It is difficult to explain. Maybe every batsman can speak for themselves individually. I don't know why this happened. Since I don't have the answer, I guess, because wickets fell regularly and the target was big, the batsmen were under pressure. Maybe that's why the batsmen gave away their wickets," said Mashrafe.

Mashrafe praised the 46-run opening stand between Tamim Iqbal and Soumya Sarkar that saw them off to a decent start in their chase of South Africa's 169/4. But the failure of others knocked Bangladesh off course.

"We started well with the bat but couldn't put on partnerships. We had problems with our decision-making. When I say decision-making, I mean shot selection. We could have gone into the last five overs with more batsmen in the shed. We could have got 60-odd in those overs but that didn't quite happen for us," said the 31-year-old.

Apart from brittle batting, Bangladesh were lacklustre in the field as well. They gave away runs cheaply with a string of misfields that included three let-offs by wicketkeeper Mushfiqur Rahim.

The poor show on the field helped South Africa openers AB de Villiers and Quinton de Kock build a sturdy foundation for the total. Mashrafe wanted his men to emulate the tourists in all aspects.

"They fielded superbly in the last game. We were fine in the first match but we gave away some twos, we had some overthrows. I won't say fielding is a serious issue but when you play against a unit of that level, you have to push yourself. Then only can you create winning opportunities," said the right arm pacer.

"We should play with cooler heads. They will come hard at us. We are not doing very badly, so we just have to hold on to our mentality, be positive and we can come back quickly."