Islamabad (AFP) - The Pakistan studies lecturer is in mid-flow when his students stand and rush for the door -- his class interrupted yet again by the call to prayer.
"They won't come back for at least 30 minutes and some of them even decide not to return to class," Sajjad Akhtar said, gathering his notes and sitting down to wait for his students to return.
At Quaid-i-Azam University, rated the best public university in Pakistan and the best Pakistani university in Asia, this is an everyday reality across all academic departments.
The university grants a 15-minute break for prayers but any student is allowed to get up as soon he hears the call to prayer in what critics call a chaotic interruption of academic life.
They say increased Islamisation in Pakistan's top teaching institutes and among the growing middle classes is helping to dumb down academic standards and restrict students' social life.
"At Quaid-i-Azam University there are four mosques, but still no bookshop," says Pervez Hoodbhoy, a nuclear physicist and one of Pakistan's most prominent academics who used to teach there.
Established in 1965 in the new federal capital Islamabad, it was considered a liberal campus until 1977 when controversial military ruler Zia-ul-Haq seized power.
During his 10-year rule, until his death in a plane crash in 1988, Zia embedded a conservative form of Islam into politics and affairs of state, and ushered in sharia law to run alongside the penal code.
Trade unions and student bodies were banned in educational institutions, and Arabic and Islamic studies were made mandatory for all students until university level.
Additional marks were given in exams to students who learned the Koran by heart. Over the subsequent generations, the trend has got deeper and more embedded.
"There are far fewer students today who can sing and dance, recite poetry, or who read novels than 20 years ago," Hoodbhoy told AFP.
"The university is very much like a school for older children, where rote-learning is considered education.
"There's no intellectual excitement, no feeling of discovery, and girls are mostly silent note-takers, you have to prod them to ask questions."
Strolling through the various departments, most female students wear the hijab -- the tight headscarf that hides all their hair and an import from the Middle East -- and none wear jeans.
None dare sit next to a man, a common sight at more liberal privately-run universities which have become the preserve of the elite as schools like Quaid-e-Azam cater to the lower and middle classes.
Though no specific place is allocated for men and women in the central cafeteria, both genders sit as far apart as possible.
Hifza Aftab, a hijab-wearing MBA student, says there is no such thing as a "liberal" girl at the university.
Any young woman who arrives on campus without wearing a hijab or the looser dupatta traditional to Pakistan quickly changes the look in two or three months, she says.
"A liberal girl would get notorious throughout the whole university," she said.
It was not always thus. Jamil Ahmed, who graduated in 1991, told AFP that in his days the hijab was rarely seen and male and female students would mingle.
Hasan Askari, a former professor at Punjab University, said students are becoming increasingly attached to religion and drifting away from rational thinking.
"The increasing Islamisation has affected quality of education as today, teachers stress more on conspiracy theories than logic," he said.
Last year a private school in Lahore dropped human reproduction from the biology syllabus after an outcry in the conservative Urdu-language press claiming it was "obscene".
Quaid-i-Azam University Vice Chancellor Masoom Yasinzai admitted academic standards had slipped over the years but insisted it was a country-wide problem and not to do with the growing focus on religion.
"Here at Quaid-i-Azam University, academic standards are not falling at an alarming rate," he said, adding that the expression "Islamisation" was being used out of context.
"We have given students the freedom to practise their religion and I think practising religion is one's individual choice."
With sectarianism and violence against minorities on the rise in Pakistan, some fear encouraging a religious mindset in universities is storing up problems for the future.
"If you have a very dominant view and very authoritarian worldview which this curriculum is teaching you, that 'You are Muslims, Islam is a good religion and other religions are not good,' that value system will create a social crisis in the society," education analyst Farzana Bari told AFP.
At one of the mosques on campus, a number of religious books are on display on the bookshelves and free for students to take away.
One of them, entitled "Put an end to obscenity" has pictures of a computer, CD player and a drum set on its cover with a red cross on top of each.
The book explains how playing music during marriage ceremonies affects "the next life" and how angels pour melted copper into the ear of anyone who listens to music or the female voice.
At the mosque, cleric Habib-u-Rehman Saleem says floods and earthquakes are God's punishment for gay sex.
"Males started to sleep with males and females started to sleep with females," he tells a group of male students.
"Some people are trying to create an environment like that of the West here, but God willing the students are religious and they will never let any such conspiracy succeed."
Touseef Ahmed Khan, chairman of the Federal Urdu University in Karachi, said he could see no change coming soon.
"A whole generation was Islamised and those who started their academic career during the Zia regime are now retiring from their jobs," he said.
"This phenomenon of Islamisation has been there for three decades, you cannot reverse it in one year -- it will take decades to do so."