Supporters of 18 opposition parties take part in a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)

Khaleda Zia (C), chairperson of Bangladesh Nationalist Party (BNP), waves to supporters during a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)

Supporters of 18 opposition parties take part in a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)

Supporters of 18 opposition parties take part in a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)

Supporters of 18 opposition parties take part in a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)

Supporters of 18 opposition parties take part in a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)

Supporters of 18 opposition parties take part in a mass rally at Motijheel area in Dhaka, capital of Bangladesh, on May 4, 2013. Bangladesh's main opposition in parliament Saturday evening slapped a 48-hour ultimatum on Prime Minister Sheikh Hasina's government to announce the restoration of a non-party caretaker government system. (Xinhua/Shariful Islam)